Synthesis of Novel Allene-Coordinated, Phosphido-Bridged Ru2Pt

Article pubs.acs.org/Organometallics

Synthesis of Novel Allene-Coordinated, Phosphido-Bridged Ru2Pt Clusters Involving Enyne to Allene Transformation Pradeep Mathur,*,†,‡,§ Dhirendra K. Rai,†,‡ Raj K. Joshi,‡,∥ Badrinath Jha,‡ and Shaikh M. Mobin†,§ †

School of Sciences, Indian Institute of Technology Indore, Khandwa Road, Indore 452017, India Department of Chemistry and §National Single Crystal X-ray Diffraction Facility, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India ∥ Department of Chemistry, Malaviya National Institute of Technology Jaipur, Jaipur 302017, India ‡

S Supporting Information *

ABSTRACT: Microwave irradiation of a toluene solution of the diyne FcC2C2Ph and Ru3(CO)12 yields the [Ru(CO)3(η4ruthenole)] derivatives 1a−f, which differ in relative positions of the uncoordinated alkyne group. Upon treatment with Pt(PPh3)2C2H4, the ruthenoles 1a−c, containing a single free CC unit at the α position with respect to the ring Ru metal, yield the novel allene-coordinated, phosphido-bridged Ru2Pt clusters 3a−c along with their phosphine-substituted derivatives 4a−c. Under similar reaction conditions, isomers 1d,e, which are devoid of any free CC unit at the α position, and 1f, having free CC units at both α positions, form only their phosphine-substituted derivatives 4d−f. The formation of Ru2Pt clusters from ruthenole complexes involves cleavage of the P−C bond of the phosphine and migration of the resulting phenyl group onto the free alkyne, which leads to enyne to allene transformation.

■

(ferrole, M = Fe;13 ruthenole, M = Ru;14 osmole, M = Os15). A characteristic feature of metalloles is that the carbonyls of the M2(CO)6 unit are in a staggered conformation, and this allows one of the carbonyls on the apical metal to interact weakly with the ring metal and thus form a semibridging carbonyl spanning the metal−metal bond, which is reflected as bending in one of the M−C−O angles from linearity (Figure 1a).16 In some less common metalloles, however, CO bridging across the metal− metal bond is thwarted by an eclipsed conformation of carbonyl groups and all carbonyl groups remain terminal (Figure 1b).17

INTRODUCTION The chemistry of metal clusters has become one of the most rapidly flourishing areas within the inorganic and organometallic fields because of their potential application in catalysis.1,2 The availability of cooperatively interacting multimetallic coordination sites in polynuclear clusters renders them as unique and superior catalysts in comparison to mononuclear complexes.3 In addition to their catalytic ability, metal carbonyl clusters have been suggested to be potential candidates in microelectronics and nanolithography.4 A widely used strategy for the synthesis of hydrocarbyl-containing metal carbonyl clusters is the condensation of polyyne complexes with coordinatively unsaturated metal fragments, which may be followed by metal−metal bond formation and eventual cluster formation.5 The reactivity of 1,3-diynes has been well explored with different metal carbonyls: in particular, those of W,6 Fe,7 Ru,8 Os,9 and Co.10 Sometimes, useful organic transformations are also observed in such reactions.11 Quite often, in the reactions of diacetylenes with metal carbonyls, only one of the CC bonds gets activated. The opportunity to react a second CC bond with metal carbonyls provides a route to highnuclearity clusters.12,9a Reactions of alkynes with group 8 metal carbonyls often leads to metallacyclopentadiene complexes as a result of metalmediated C−C bond formation, also known as metalloles © XXXX American Chemical Society

Figure 1. Staggered and eclipsed conformations of M2(CO)6 units of the metalloles with semibridging (a) and terminal carbonyls (b). Received: May 27, 2014

A

dx.doi.org/10.1021/om500561b | Organometallics XXXX, XXX, XXX−XXX

Organometallics

Article

IR and 1H and 13C NMR spectroscopy and mass spectrometry. The IR spectra of ruthenole isomers show terminal carbonyl stretching frequencies in the range 2079−1958 cm−1, except for 1f, where an additional weak peak at the low wavenumber 1909 cm−1 corresponding to a semibridging carbonyl was also observed. In the case of diruthenacycloheptadienone complexes 2a−e, in addition to terminal carbonyl peaks (2089−1958 cm−1), conjugated ketonic νCO vibrations (1692−1686 cm−1) can be clearly seen. In mass spectra, prominent peaks at m/z 992 and 1020 correspond to molecular ion peaks for complexes 1 and 2, respectively. In addition to ferrocenyl, phenyl, alkynyl, and metal carbonyl carbon signals in the 13C NMR spectra of 1 and 2, a peak for ketonic carbon also appears in the case of 2. Although a similar pattern in FT-IR and mass spectra for isomers of 1 and 2 did not give any information beyond core structures, nevertheless, NMR studies became helpful in distinguishing the symmetrically and asymmetrically substituted isomers. Moreover, molecular structures of 1a,c−f and 2a were further unambiguously established by their single-crystal X-ray diffraction studies, which confirm that the isomers a−f of 1 and 2 differ in relative positions of Ph, Fc, PhCC, and FcCC substituents on the ruthenacyclopentadiene and diruthenacycloheptadienone rings. Previous studies have suggested that, in such C−C coupling reactions of asymmetric butadiynes, the acetylenic bond adjacent to the ferrocene group is more likely to participate in coupling than that next to the phenyl group.7b,c,8b,23 However, contrary to this notion, under microwave conditions, we were able to isolate compounds arising from all three possible coupling combinations of acetylenes (Scheme S1 in the Supporting Information): (i) head to head coupling of two CC units adjacent to the ferrocenyl moiety (1a,d and 2a,d), (ii) head to tail coupling of two CC units adjacent to phenyl and ferrocenyl moieties (1b,e and 2b,e), and (iii) tail to tail coupling of two CC units adjacent to the phenyl moiety (1c,f and 2c). Microwave irradiation plays a crucial role in the present reaction, as under thermolytic or photolytic conditions, only head to head and head to tail coupled products are formed, whereas isomers featuring tail to tail coupling (1c,f and 2c) were not observed (experimental details are given in the Supporting Information). Although the microwave dielectric loss of toluene is low (ε″ = 0.07),24 there are some reports on microwave-assisted reactions using toluene as solvent.25 The present study, in contrast to previous reports, shows that the acetylenic units FcCC and PhCC are both equally reactive and it is possible to design products arising from all possible couplings by applying appropriate reaction conditions.

Metalloles have been identified as stable intermediates in cyclomerization reactions of unsaturated organic species,18 and there exist numerous other reports on complexes of the type [M(CO)3(η4-metallole)].19 Our investigations on the effect of substituents and reaction conditions on the reactivity of butadiynes toward metal carbonyls led us to a very rare observation where both types of ruthenoles were isolated from the single reaction of FcC4Ph and Ru3(CO)12 (Scheme 1). To investigate the reactivity of the two types of ruthenoles, we chose a popular electron-deficient and labile Pt(PPh3)2(C2H4) reagent for our study, because Pt-based heterometallic clusters, owing to their structural flexibility and rich chemistry, have attracted great synthetic interest and have found applications in catalysis and the materials science field.20 Moreover, electrondeficient metal phosphine complexes are known to undergo P− C bond cleavage, which stabilizes the higher nuclearity clusters through formation of a phosphide or phosphinidene bridge,21 and act as versatile intermediates in organic synthesis.22 In this paper, we discuss the contrasting behavior of different alkynyl-substituted ruthenoles toward Pt(PPh3)2C2H4 reagent and report on a series of novel mixed Ru/Pt clusters, whose formation results from reactivity emanating from ruthenole derivatives having a free alkynyl moiety at the α position with respect to the ring metal.

■

RESULTS AND DISCUSSION Synthesis of Ru(CO)3(η4-ruthenole) Derivatives 1a−f. When a toluene solution of 1-ferrocenyl-4-phenyl-1,3-diyne and Ru3(CO)12 was stirred under microwave radiation at 80 °C for 25 min, derivatives of Ru(CO)3(η4-ruthenacyclopentadiene) (1a−f) and diruthenaheptadienone (2a−e) were formed as a result of metallacyclocoupling of CC and Ru metal units (Scheme 1). Each of the new compounds was characterized by Scheme 1. Reaction of FcC4Ph with Ru3(CO)12

Figure 2. Structures of typical C4Ru2(CO)6 cores of 1a−e (a) and 1f (b). B


Organometallics

Article

Figure 3. (a) Molecular structure of [Ru(CO)3{η2:η2-(Fc)CC(CCPh)C(Fc)C(CCPh)Ru(CO)3}] (1a). (b) C4Ru2 core of 1a with eclipsed orientation of carbonyls. Selected bond lengths (Å) and bond angles and dihedral angles (deg): Ru(1)−Ru(2) = 2.6715(9), Ru(1)−C(11) = 2.049(4), Ru(2)−C(12) = 2.232(4), Ru(2)−C(11) = 2.347(4), C(11)−C(12) = 1.424(5), C(7)−C(12) = 1.478(5), C(8)−C(9) = 1.407(5); C(11)−Ru(1)−C(8) = 78.48(15), C(7)−C(8)−Ru(1) = 117.6(3), C(8)−C(7)−C(12) = 113.0(3), Ru(1)−C(3)−O(3) = 177.2(4); C(3)− Ru(1)−Ru(2)−C(4) = 13.1(3), C(1)−Ru(1)−Ru(2)−C(6) = 12.5(2).

Figure 4. (a) Molecular structure of [Ru(CO)2{η2:η2-FcCC)CC(Ph)C(Ph)C(CCFc)Ru(CO)3}-μ-CO] (1f). (b) C4Ru2 core of 1f with a staggered orientation of carbonyls and bending of one of the apical carbonyls. Selected bond lengths (Å) and bond angles and dihedral angles (deg): Ru(1)− Ru(2) = 2.7273(6), Ru(1)−C(12) = 2.293(4), Ru(1)−C(11) = 2.312(5), Ru(2)−C(8) = 2.080(4), C(7)−C(8) = 1.441(6), C(7)−C(11) = 1.450(5);, C(8)−Ru(2)−C(12) = 77.54(17), C(8)−C(7)−C(11) = 114.3(4), Ru(1)−C(1)−O(1) = 167.9(5), Ru(1)−C(2)−O(2) = 176.9(6), Ru(2)−C(5)−O(5) = 176.8(4); C(4)−Ru(2)−Ru(1)−C(1) = 39.9(3), C(6)−Ru(2)−Ru(1)−C(1) = 64.3(3), C(5)−Ru(2)−Ru(1)−C(1) = 8.3(3).

The molecular structures and detailed metric parameters for complexes 1a,f and 2a are given in Figures 3−5, respectively, while those of 1c−e are given in Figures S1−S3 (Supporting Information), respectively. The semibridging carbonyls play an important role as intermediates in the intramolecular exchange of CO groups in the clusters and also in exchange between terminal and symmetrically bridged carbonyls.26 Though the interaction between semibridging carbonyl and the second metal is relatively weak, nevertheless, it greatly influences the reactivity of metal carbonyl complexes.27 One such example is biomimetic hydrogenase activity of dithiolate-bridged di-, tri-, and tetrairon carbonyl complexes, in which the presence of a semibridging carbonyl, arising from the staggered conformation with a very low energy barrier, is believed to be the key feature of proton reduction.28 The activity of these hydrogenase biomimics can be improved by controlling rotation of the Fe− Fe bond through introduction of bulkier chelating groups.29

The molecular structures of 1a−e show an eclipsed conformation of carbonyls on the two ruthenium centers with dihedral angles between equatorial Ruapical−CO and Ruring−CO bonds ranging from 0.6 to 16.6°. This particular arrangement geometrically prevents an apical carbonyl to be close enough to the ring Ru metal for a CO bridge formation; hence, all carbonyls remain terminal with almost linear Ru−C− O angles (average Ru−C−O angle 177°) (Figure 2a). Interestingly, in contrast to 1a−e, the molecular structure of 1f reveals a routine staggered conformation of carbonyls with dihedral angles between one of the Ruapical−CO and two equatorial Ruring−CO bonds being 39.9(3) and 64.3(3)°. The staggered orientation in 1f allows an apical carbonyl to come sufficiently close to the ring Ru metal (2.71 Å in 1f in comparison to an average of 3.10 Å in 1a−e) for a weak interaction leading to the formation of a semibridging carbonyl across the Ru−Ru bond, which causes bending in one of the apical Ru−C−O angles (Ru−C−O =167.8(6)°) (Figure 2b). C


Organometallics

Article

Figure 5. (a) Molecular structure of [Ru2(CO)6{μ-η1:η1: η2:η2-(Fc)CC(CCPh)C(O)C(Fc)C(CCPh)}] (2a). (b) OC4Ru2 core structure of 2a showing a flyover arrangement of the OC4 unit. Selected bond lengths (Å) and bond angles (deg): Ru(1)−Ru(2) = 2.7151(8), Ru(1)−C(8) = 2.074(5), Ru(1)−C(13) = 2.232(5), Ru(1)−C(12) = 2.315(5), C(1)−C(12) = 1.466(7), C(12)−C(13) = 1.401(7); C(8)−Ru(1)−C(13) = 87.1(2), C(8)−Ru(1)−C(12) = 81.1(2), C(13)−Ru(2)−C(8) = 85.7(2), C(12)−C(1)−C(9) = 114.1(5), O(6)−C(6)−Ru(2) = 175.2(7).

Reactivity of 1a−f toward Pt(PPh3)2C2H4. On the basis of substituent positions, ruthenole isomers can be categorized into three sets: (i) 1a−c having two free CC moieties at alternate α and β positions with respect to the ring Ru metal, (ii) 1d,e having both free alkynes at β positions, and (iii) 1f having both free alkynes at α positions. In order to test the reactivity of these metallole isomers bearing free alkynyl groups at different positions of their C4Ru ring, we further reacted 1a− f with Pt(PPh3)2C2H4 (Scheme 2). It was observed that the course of these reactions is dependent on the position of the free alkyne groups on the ruthenacyclopentadiene ring. When compound 1a was heated with Pt(PPh3)2C2H4 in toluene solvent for 6 h at 100 °C, two products were isolated: the novel mixed-metal Ru2Pt cluster 3a and the phosphinesubstituted derivative 4a. From the reactions of 1b,c, in addition to their phosphine derivatives 4b,c, two geometrical isomers of Ru2Pt clusters (3b1,b2 and 3c1,c2), differing in the relative orientations of Fc and Ph groups at the allene terminal carbon, were isolated. Under similar conditions, the reactions of 1d,e afford only the phosphine-substituted products 4d,e. These observations suggest that the presence of an uncoordinated CC moiety at the α position with respect to the ring Ru atom favors the Ru2Pt cluster formation. However, despite having two free CC groups at the required positions, 1f yields only the phosphine-ligated complex 4f. The different reactivity of 1f in comparison to 1a−c may be attributed to steric factors arising due to the presence of two FcCC− units at α positions, which might also be the reason for the semibridging carbonyl in 1f. The new Ru2Pt clusters 3a−c and phosphine-substituted derivatives 4a−f were all characterized by IR and 1H, 13C, and 31 P NMR spectroscopy and by mass spectrometry. The νCO frequencies in the IR spectra of 4a−f indicate the presence of a monosubstituted Ru2(CO)5PPh3 unit, whereas the mixed-metal clusters 3a−c show the presence of terminal carbonyls for the Ru2(CO)5Pt(CO) moiety. The 13C NMR spectra of clusters show a substantial upfield shift for Pt-coordinated olefin carbons, which is consistent with earlier reports.30 In 31P NMR spectra, a peak at ∼−20 ppm, flanked by two satellite bands due to coupling of Pt (1JPtP ≈ 2970 Hz), arises for the phosphido bridge of clusters, whereas for 4a−f, the phosphine phosphorus

Scheme 2. Reactions of 1a−f with Pt(PPh3)2C2H4

resonates at ∼45 ppm. In addition to the molecular ion peaks of 3 and 4, isotopic mass patterns corresponding to the empirical formulas of 3a−c can also be seen in their mass spectra (Figure S4 in the Supporting Information). Crystallographic studies were carried out on single crystals of 3a,b2 and 4d, grown by slow evaporation of their solutions in a dichloromethane/hexane solvent mixture; molecular structures D


Organometallics

Article

Figure 6. (a) Molecular structure of [Ru(CO)2{η3-(Fc)CC(CCPh)C(Fc)C(μ2-CCC(Ph)2)Ru(CO)3Pt(CO)(μ2-PPh2)] (3a). (b) Core structure of the Ru2Pt cluster showing η3 coordination of the C4Ru ring to apical Ru metal, η2 coordination of one of the CC bonds of allene to Pt metal, and a phosphido bridge across the Ru−Ru bond. Selected bond lengths (Å) and bond angles (deg): Ru(1)−Ru(2) = 2.8253(7), Pt(1)−Ru(1) = 2.8650(7), Pt(1)−Ru(2) = 2.9096(7), Pt(1)−P(1) = 2.2700(16), Ru(1)−P(1) = 2.296(2), Pt(1)−C(12) = 2.231(6), Pt(1)−C(13) = 2.121(6), C(7)−C(8) = 1.443(8), C(8)−C(11) = 1.454(9), C(11)−C(12) = 1.466(8), C(12)−C(13) = 1.404(9), C(13)−C(14) = 1.334(8); Ru(1)−Pt(1)− Ru(2) = 58.577(16), Ru(2)−Ru(1)−Pt(1) = 61.501(17), Ru(1)−Ru(2)−Pt(1) = 59.922(17), Pt(1)−P(1)−Ru(1) = 77.72(5), C(14)−C(13)− C(12) = 148.0(6).

Figure 7. (a) Molecular structure of [Ru(CO)2{η3-(Fc)CC(CCPh)C(Ph)C(μ2-CCC(Fc)(Ph))Ru(CO)3Pt(CO) (μ2-PPh2)] (3b2). (b) Core structure of the Ru2Pt cluster showing η3 coordination of the C4Ru ring to apical Ru metal, η2 coordination of one of the CC bonds of allene to Pt metal, and a phosphido bridge across the Ru−Ru bond. Selected bond lengths (Å) and bond angles (deg): Ru(1)−Ru(2) = 2.8224(11), Pt(1)− Ru(1) = 2.9100(11), Pt(1)−Ru(2) = 2.9847(11), Pt(1)−P(1) = 2.280(2), Ru(1)−P(1) = 2.334(2), Pt(1)−C(12) = 2.282(8), Pt(1)−C(13) = 2.110(8), C(7)−C(8) = 1.444(11), C(7)−C(11) = 1.437(11), C(11)−C(12) = 1.445(11), C(12)−C(13) = 1.431(11), C(13)−C(14) = 1.331(12); Ru(1)−Pt(1)−Ru(2) = 57.20(3), Ru(2)−Ru(1)−Pt(1) = 62.73(3), Ru(1)−Ru(2)−Pt(1) = 60.07(3), Pt(1)−P(1)−Ru(1) = 78.19(7), C(13)− Pt(1)−C(12) = 37.8(3), C(14)−C(13)−C(12) = 139.9(9).

cyclopent-1-ene ring, where the ring Ru(CO)3 unit is covalently bonded to another apical Ru(CO)2 and a Pt−CO moiety. The Ruapical atom is also covalently linked to platinum metal and caps the ruthenacyclopentene ring in a η3 fashion. In addition to coordination to both ruthenium atoms, the platinum atom is

of 3a,b2 are shown in Figures 6 and 7, respectively. Crystallographic data for 4d are relatively weak but nevertheless clearly show the site of phosphine substitution (Figure S5 in the Supporting Information). The molecular structures of clusters 3a,b2 reveal them to consist of a 4-vinylideneruthenaE


Organometallics

Article

η2 coordinated to a CC bond of an allene moiety lying in the coordination plane. In the Ru2Pt triangular arrangement, one of the Pt−Ru bonds is further stabilized by a phosphido bridge. The five- and three-membered rings C4Ru and Ru2Pt both share a common Ru(2) vertex, and the angle between their planes is around 49°. The Ru(1)−Ru(2) bond distances in 3a,b2 at 2.8253(7) and 2.8224(11) Å, respectively, show considerable elongation from that in 1a at 2.6715(9) Å. These are shorter than 3.043(2) Å in [Pt3Ru6(CO)21(μ-H)3(μ3− H)]31 and 2.9219(8) Å in [Ru4(CO)12Pt(CO)PPh3(μ4-PN(iPr)2]21 but longer than the average Ru−Ru bond length of 2.789 Å in [Ru6(PhCHC3C6H4)2(CO)15)].12 Because of the phosphido bridging, the Pt−Ruapical bond (3a, 2.8650(7) Å; 3b2, 2.9100(11) Å) is shorter than the Pt−Ruring bond (3a, 2.9096(7) Å; 3b2, 2.9847(11) Å) but longer than that in the related Ru/Pt clusters [Ru4(CO)9Pt(CO)PPh3(μ3-PNiPr2)] (2.828 Å),21 [Ru2Pt(CO)7(PPh3)2(PhC2Ph)] (2.793 Å),32 and [Pt3Ru6(CO)21(μ-H)3(μ3-H)] (2.708(2) Å).31 Within the RuPtP triangle, the Ru(1)−P(1) (3a, 2.2700(16) Å; 3b2, 2.334(2) Å) and Pt(1)−P(1) (3a, 2.296(2) Å; 3b2, 2.280(2) Å) bond distances are similar to those in [Ru5PtC(CO)13(μPPh2)2] (2.277(3) and 2.274(3) Å).33 Elongation of the C(11)−C(12) bond from 1.408(8) Å in 1a to 1.466(8) Å in 3a is indicative of CC to C−C bond transformation. Also, in comparison to 1a, compression of the C(12)−C(13) bond length from 1.409(83) to 1.4043(1) Å and elongation of the C(13)−C(14) bond from 1.178(91) to 1.3340(1) Å in 3a accentuate enyne to allene transformation. As a result of Pt coordination, the two CC bonds of the allene moiety are no longer the same in length (3a, C(12)− C(13) = 1.4043(1) Å, C(13)−C(14) = 1.3340(1) Å; 3b2, C(12)−C(13) = 1.431(11) Å, C(13)−C(14) = 1.331(12) Å) and the CCC angles of both clusters show substantial deviation from linearity (C(12)−C(13)−C(14) = 148.0(6)° (3a), 139.9(9)° (3b2)). The greater deviation in allene C CC angle in 3b2 reflects stronger Pt to allene coordination mainly due to the presence of a ferrocenyl group on the allene terminal carbon. In the Pt-coordinated allene part, Pt−η2-(C C), both Pt−C bond lengths (3a, Pt(1)−C(12) = 2.2312(85) Å, Pt(1)−C(13) = 2.1296(61) Å; 3b2, Pt(1)−C(12) = 2.2695(4) Å, Pt(1)−C(13) = 2.1196(4) Å) are significantly different and compare well with those of the reported Pt−allene complexes [(Ph3P)2Pt(C3H2F2)],30b [(PPh3)2Pt(C3H2Me2)],34 and [(PPh3)2Pt(C3H4)].35 The following rationalization can be made: in the case of a strongly π basic Pt(0) metal, the Pt−η2(CC) complex is expected to adopt a metallacyclopropane type structure, in which sp3- and sp2-hybridized carbon orbitals are involved in the formation of Pt(1)−C(12) and Pt(1)− C(13) bonds, respectively. In general, the molecular structure of 4d (Figure S5 in the Supporting Information) is similar to that of its parent compound 1d, where one of the apical carbonyls is replaced by a phosphine group. Ligation of the bulky PPh3 ligand to the sterically more open Ruapical instead of the Ruring center suggests that steric factors play a decisive role in the formation of phosphine-substituted products. Ru(1)−Ru(2) and all ring plane Ru−C and C−C bond lengths are similar to those in 1d. The Ru−P bond of 4d at 2.3617(13) Å is similar to that in 3b2 but longer than that in 3a and that in [Ru5PtC(CO)13(μPPh2)2] (2.277(3) Å).33 Plausible Mechanism for Ru2Pt Cluster Formation. Cluster formation is accompanied by the following changes: (i) a change in bonding mode of Ruapical from η4 to η3 and (ii) P−

C bond cleavage of the PPh3 unit and migration of the resulting phenyl to the CC bond at the α position, leading to enyne to allene transformation. There are examples of dephenylation as a result of P−C bond cleavage of the cluster-bound phosphines. The dephenylation can occur as benzene after abstraction of a metal-bonded hydrogen.36 However, it can also be followed by reattachment to another part of cluster through M−C37 or C−C38 bond formation. Although the exact mechanism for the formation of the Ru2Pt cluster cannot be confirmed at present, in accordance with the above observations, a plausible mechanism for formation of the Ru2Pt cluster is depicted in Scheme 3. The Scheme 3. Plausible Mechanism for Formation of Ru2Pt Clusters 3a−c

Ru2Pt cluster formation can be thought to proceed from intermediate i, formed by initial ligation of Pt(PPh3)2 to uncoordinated acetylene attached to the α carbon of the ruthenacyclopentadiene ring. Subsequent CO and PPh3 removal from Ruapical and Pt, respectively, leads to formation of intermediate ii, which undergoes oxidative addition of a phosphine through P−Ph bond cleavage and forms intermediate iii, having a Pt−Ph σ bond and a phosphido bridge across the Ru−Pt bond. The formation of iii may be justified by the fact that, under thermolytic conditions, formation of analogous systems from P−Ph bond cleavage of Pt(PPh3)2(C2H4) has been reported in the literature.39 In addition, oxidative addition of metal-coordinated tertiary phosphines to the same metal unit as a result of P−C bond cleavage is well known.22,40 In the final step, substitution of Ph by an incoming CO and its migration to the acetylene carbon lead to an enyne to allene transformation. This step can be speculated to be Lewis acid or thermally induced migration of phenyl from platinum to olefin, as has been observed for platinum phenyl olefin complexes having hemilabile ligands.41 The enyne to allene transformation translates into a change in bonding mode from η4 to η3 between Ruapical and the ruthenacyclopentene ring and leads to the formation of an allene-coordinated, phosphido-bridged Ru2Pt cluster. The formation of two geometrical isomers in the case of 1b,c (where R4 is not phenyl) may be rationalized by two possible paths of Ph migration to the acetylenic carbon. F


Organometallics

■

Article

C5H5), 4.23 (s, 5H, η5-C5H5), 4.19−4.89 (m, 8H, η5-C5H4), 7.30−7.41 (m, 10H, C6H5); 13C NMR (CDCl3) δ 127.1−134.8 (m, C6H5), 67.9− 69.1 (η5-C5H4), 69.4 (η5-C5H5), 70.3 (η5-C5H5), 83.7−99.1 (m, PhC C, PhCC, FcCC, FcCC), 103.2−121.4 (m, C4Ru), 197.0, 197.3 (Ru-CO); MS (m/z, ES+) 992 (M + ). Anal. Calcd for C46H28Fe2O6Ru2: C, 55.78; H, 2.85. Found: C, 56.17; H, 2.88. 1c: yield 5 mg, 3%; IR (νCO, cm−1) 2080 (s), 2052 (vs), 2017 (s), 200 (w), 1980 (w), 1958 (w); 1H NMR (CDCl3) δ 4.13 (s, 5H, η5C5H5), δ 4.23 (s, 5H, η5-C5H5), 4.20−4.34 (m, 8H, η5-C5H4), 7.44− 7.66 (m, 10H, C6H5); MS (m/z, ES+) 992 (M+). Anal. Calcd for C46H28Fe2O6Ru2: C, 55.78; H, 2.85. Found: C, 56.23; H, 2.86. 1d: yield 19 mg, 13%; IR (νCO, cm−1) 2078 (s), 2049 (vs), 2015 (s), 1985 (w), 1973 (w) 1958 (w); 1H NMR (CDCl3) δ 4.15 (s, 10H, η5C5H5), 4.31−4.89 (m, 8H, η5-C5H4), 7.38−7.60 (m, 10H, C6H5); 13C NMR (CDCl3) δ 128.6−132.7 (m, C6H5), 68.7−69.8 (m, η5-C5H4), 71.0 (s, η5-C5H5), 96.9, 98.7 (PhCC, PhCC), 114.5, 146.1 (C4Ru), 192.1 (Ru-CO); MS (m/z, ES+) 992 (M+). Anal. Calcd for C46H28Fe2O6Ru2: C, 55.78; H, 2.85. Found: C, 55.50; H, 2.82. 1e: yield 13 mg, 9%; IR (νCO, cm−1) 2079 (vs), 2052 (vs), 2015 (s), 1996 (w), 1978 (w); 1H NMR (CDCl3) δ 4.20 (s, 5H, η5-C5H5), 4.25 (s, 5H, η5-C5H5), 4.32−5.01 (m, 8H, η5-C5H4), 7.41−7.67 (m, 10H, C6H5); 13C NMR (CDCl3) δ 128.2−133.5 (m, C6H5) 67.2−69.9 (m, η5-C5H4), 71.8 (η5-C5H5), 73.2 (η5-C5H5), 123.5−148.7 (C4Ru), 84.0− 94.6 (m, PhCC, PhCC, FcCC, FcCC), 196.0, 196.4, 197.9 (Ru-CO); MS (m/z, ES+) 992 (M + ). Anal. Calcd for C46H28Fe2O6Ru2: C, 55.78; H, 2.85. Found: C, 56.31; H, 2.81. 1f: yield 8 mg, 5%; IR (νCO, cm−1) 2079 (m), 2051 (s), 2014 (br), 1977 (w), 1958 (w), 1909 (vw, br); 1H NMR (CDCl3) δ 4.21 (s, 10 H, η5-C5H5), 4.41−4.73 (m, 8H, η5-C5H4), 7.36−7.53 (m, 10H, C6H5); MS (m/z, ES+) 992 (M+). Anal. Calcd for C46H28Fe2O6Ru2: C, 55.78; H, 2.85. Found: C, 55.28; H, 2.89. 2a: yield 13 mg, 8%; IR (νCO, cm−1) 2088 (m), 2066 (vs), 2044 (w), 2026 (vs), 2005 (w), 1958 (w), 1686 (wbr); 1H NMR (CDCl3) δ 4.19 (s, 5 H, η5-C5H5), 4.25 (s, 5 H, η5-C5H5), 4.47−5.02 (m, 8H, η5C5H4), 7.31−7.68 (m, 10H, C6H5); MS (m/z, ES+): 1020 (M+). Anal. Calcd for C47H28Fe2O7Ru2: C, 55.42; H, 2.77. Found: C, 55.97; H, 2.79. 2b: yield 8 mg, 5%; IR (νCO, cm−1) 2088 (w), 2066 (m), 2046 (w), 2027 (vs), 1958 (m), 1686 (w); 1H NMR (CDCl3) δ 4.22 (s, 5H, η5C5H5), 4.33 (s, 5H, η5-C5H5), 4.88−4.98 (m, 8H, η5-C5H4), 7.32−7.59 (m 10H, C6H5); 13C NMR (CDCl3) δ 128.5−132.7 (m, C6H5), 66.9− 70.1 (m, η5-C5H4), 72.9 (η5-C5H5), 73.6 (η5-C5H5), 141.3, 111.1, 149.8, 123.6 (PhCC, PhCC, FcCC, FcCC), 84.5−98.0 (m, PhCC, PhCC, FcCC, FcCC), 167.9 (CO), 188.9, 191.3, 195.7 (Ru-CO); MS (m/z, ES+) 1018 (M+). Anal. Calcd for C47H28Fe2O7Ru2: C, 55.42; H, 2.77. Found: C, 56.02; H, 2.80. 2c: yield 6 mg, 4%; IR (νCO, cm−1) 2089 (s), 2067 (vs), 2050 (w), 2027 (vs), 2004 (w), 1958 (w), 1692 (w); 1H NMR (CDCl3) δ 4.05 (s, 5H, η5-C5H5), 4.12 (s, 5H, η5-C5H5), 4.20−4.32 (m, 8H, η5-C5H4), 7.32−7.80 (m 10H, C6H5); 13C NMR (CDCl3) δ 127.8−131.8 (m, C6H5), 66.8−69.9 (m, η5-C5H4), 71.8 (η5-C5H5), 72.4 (η5-C5H5), 140.9, 112.2, 147.3, 122.6 (PhCC, PhCC, FcCC, FcCC), 84.5−98.0 (m, FcCC, FcCC), 166.4 (CO), 196.4 (Ru-CO); MS (m/z, ES+) 1020 (M+). Anal. Calcd for C47H28Fe2O7Ru2: C, 55.42; H, 2.77. Found: C, 55.03; H, 2.82. 2d: yield 11 mg, 7%; IR (νCO, cm−1) 2088 (m), 2066 (vs), 2045 (w), 2026 (vs), 2006 (w), 1958 (w), 1689 (wbr); 1H NMR (CDCl3) δ 4.25 (s, 10 H, η5-C5H5), 4.51−4.93 (m, 8H, η5-C5H4), 7.39−7.66 (m, 10H, C6H5); 13C NMR (CDCl3) δ 128.5−132.6 (m, C6H5), 66.9− 70.6(m, η5-C5H4), 72.9 (η5-C5H5), 138.7, 123.8 (FcCC, FcCC), 93.1, 91.7 (PhCC, PhCC),160.1 (CO), 194.6, 195.7 (Ru-CO); MS (m/z, ES+) 1020 (M+). Anal. Calcd for C47H28Fe2O7Ru2: C, 55.42; H, 2.77. Found: C, 56.01; H, 2.84. 2e: yield 10 mg, 7%; IR (νCO, cm−1) 2089 (s), 2067 (vs), 2050 (w), 2027 (vs), 2004 (w), 1958 (w), 1692 (w); 1H NMR (CDCl3) δ 4.22 (s, 5H, η5-C5H5), 4.25 (s, 5H, η5-C5H5), 4.21−4.84 (m, 8H, η5-C5H4), 7.30−7.59 (m, 10H, C6H5); 13C NMR (CDCl3) δ 127.8−132.1 (m, C6H5), 66.4−70.2 (m, η5-C5H4), 71.5 (η5-C5H5), 72.3 (η5-C5H5), 143.4, 105.4, 159.4, 123.1 (PhCC, PhCC, FcCC, FcCC), 95.1, 88.9, 90.4, 83.2 (PhCC, PhCC, FcCC, FcCC), 168.0

CONCLUSION In conclusion, we have demonstrated the synthesis of a series of novel mixed-metal Ru/Pt clusters by exploiting the pendant alkynes on ruthenole precursors. The Ru/Pt cluster formation requires a necessary condition of an uncoordinated alkyne being present at the α position with respect to Ruring of ruthenole, whereas a ruthenole bearing an uncoordinated alkyne at both α positions does not form a Ru/Pt cluster possibly because of steric reasons. We have also established that, in cyclocoupling reactions of unsymmetrical butadiynes on a metal carbonyl framework, it is possible to obtain metallacyclocoupled products arising from all possible couplings by applying the appropriate reaction conditions.

■

EXPERIMENTAL SECTION

General Procedure. All reactions and manipulations were performed using standard Schlenk line techniques under an inert atmosphere of dry, prepurified argon or nitrogen. Solvents were purified, dried, and distilled under an argon atmosphere prior to use. Infrared spectra were recorded on a Nicolet 380 FT-IR spectrometer as hexane solutions in 0.1 mm path length NaCl cells and NMR spectra on a Varian VXRO-300S spectrometer in CDCl3. Electrospray mass spectra were recorded on a Micromass Q-ToF mass spectrometer. Ru3(CO)12 was purchased from Strem Chemicals and used as received. Pt(C2H4)(PPh3)2 was purchased from Acros Organics and used as received. Analytical-grade high-performance TLC plates were purchased from Merck (20 × 20 cm silica gel 60 F254). Microwave Reaction of 1-Ferrocenyl-4-phenyl-1,3-butadiyne and Ru3(CO)12. In a 100 mL two-necked round-bottom flask, FcC4Ph (0.0930 g, 0.3 mmol) was dissolved in freshly dried toluene (10 mL), to which Ru3(CO)12 (0.256 g, 0.4 mmol) was added. The reaction mixture was then placed in a microwave reactor (multimode reactor: ETHOS Synth Lab Station (Ethos start, Milestone Inc.)) and exposed to 2.45 GHz microwave radiation at maximum 1000 W power in 10 W increments (pulsed irradiation). In order to absorb the microwave energy in the absence of any polar solvent, a Teflon-coated magnetic stirring bar was used in the reaction, which in turn transfers the absorbed energy to the reaction mixture. The temperature was measured throughout the reaction and evaluated by an inbuilt infrared detector, which indicated the surface temperature. A program for the reaction, where T1 (acquiring time) for 10 min, T2 (irradiation time) at 80 °C for 15 min, and T3 (cooling time to reach room temperature) for 10 min, was set using the “easy WAVE” software package installed in the microwave reactor. The progress of the reaction was followed by TLC at intervals of 3 min. After completion of the reaction, the solvent was evaporated at reduced pressure and the solid residue was loaded in the column for chromatographic workup. Starting with a 5/95 CH2Cl2/hexane solvent mixture and gradually increasing the polarity to a 30/70 CH2Cl2/ hexane solvent mixture, three fractions were collected separately: (i) an orange fraction containing a mixture of 1a−f, (ii) a maroon fraction containing a mixture of 2a−c, and (iii) a dark maroon fraction containing a mixture of 2d and 2e. The collected fractions i−iii were dried and again subjected to chromatographic workup using analyticalgrade high-performance TLC plates with 5/95, 15/85, and 25/75 CH2Cl2/hexane mixtures, respectively, which after elution with neat CH2Cl2 yielded the corresponding pure compounds. 1a: yield 22 mg, 14%; IR (νCO, cm−1) 2078 (s), 2051 (vs), 2015 (vs), 1996 (w), 1978 (w), 1958 (w); 1H NMR (CDCl3) δ 4.21 (s, 5H, η5-C5H5), 4.25 (s, 5H, η5-C5H5), 4.22−4.91 (m, 8H, η5-C5H4), 7.31− 7.38 (m, 10H, C6H5); 13C NMR (CDCl3) δ 128.3−134.5 (m, C6H5), 68.3−69.5 (m, η5-C5H4), 69.6 (s, η5-C5H5), 70.4 (s, η5-C5H5), 93.8− 96.9 (m, PhCC, PhCC), 104.0−123.4 (m, η4-C4Ru), 195.9, 196.1, 196.9 (Ru-CO); MS (m/z, ES+) 992 (M+). Anal. Calcd for C46H28Fe2O6Ru2: C, 55.78; H, 2.85. Found: C, 56.11; H, 2.89. 1b: yield 14 mg, 9%; IR (νCO, cm−1) 2078 (s), 2050 (vs), 2016 (vs), 1996 (w), 1978 (w), 1959 (w); 1H NMR (CDCl3) δ 4.22 (s, 5H, η5G


Organometallics

Article

4c: yield 6 mg, 25%; IR (cm−1, νCO) 2049 (w), 1992 (s), 1970 (m); H NMR (CDCl3) δ 4.05 (s, 5H, η5-C5H5), δ 4.21 (s, 5H, η5-C5H5), 4.19−4.33 (m, 8H, η5-C5H4), 7.42−7.67 (m, 25H, C6H5); 31P NMR (CDCl3) δ 43.13; MS (m/z, ES+) 1226 (M+). Anal. Calcd for C63H43Fe2O5PRu2: C, 61.78; H, 3.54. Found: C, 62.33; H, 3.59. 4d: yield 15 mg, 63%; IR (cm−1, νCO) 2047 (s), 2000 (s), 1977 (s); 1 H NMR (CDCl3): δ 4.15 (s, 10H, η5-C5H5), 4.30 (m, 8H, η5-C5H4), 7.37−7.61 (m, 25H, C6H5); 13C NMR (CDCl3) δ 128.6−132.7 (m, C6H5), 68.2−69.3 (m, η5-C5H4), 71.1 (s, η5-C5H5), 76.6, 78.7 (PhC C, PhCC−) 113.3, 145.9 (C4Ru), 189.9 (Ru-CO); 31P NMR (CDCl3) δ 42.34; MS (m/z, ES+) 1226 (M+). Anal. Calcd for C63H43Fe2O5PRu2: C, 61.78; H, 3.54. Found: C, 62.36; H, 3.62. 4e: yield 14 mg, 59%; IR (cm−1, νCO) 2047 (s), 2000 (s), 1977 (s); 1 H NMR (CDCl3): δ 4.19 (s, 5H, η5-C5H5), 4.25 (s, 5H, η5-C5H5), 4.30- 5.39 (m, 8H, η5-C5H4), 7.40−7.65 (m, 25H, C6H5); 13C NMR (CDCl3) δ 128.1−133.5 (m, C6H5) 67.2−69.7 (m, η5-C5H4), 71.8 (s, η5-C5H5), 73.2 (s, η5-C5H5), 122.5−148.3 (C4Ru), 84.2−94.7 (m, PhCC, PhCC, FcCC, FcCC), 192.1, 195.8 (Ru-CO); 31P NMR (CDCl3) δ 43.09; MS (m/z, ES+) 1226 (M+). Anal. Calcd for C63H43Fe2O5PRu2: C, 61.78; H, 3.54. Found: C, 62.40; H, 3.60. 4f: yield 12 mg, 51%; IR (cm−1, νCO) 2079 (m), 2051 (s), 2014 (sbr), 1977 (w), 1958 (w); 1H NMR (CDCl3) δ 4.21 (s, 10 H, η5C5H5), 4.41−4.72 (m, 8H, η5-C5H4), 7.35−7.52 (m, 25H, C6H5); 31P NMR (CDCl3) δ 41.55 MS (m/z, ES+) 1226 (M+). Anal. Calcd for C63H43Fe2O5PRu2: C, 61.78; H, 3.54. Found: C, 62.58; H, 3.61. Crystal Structure Determination of Compounds 1a,c−f, 2a, 3a,b2, and 4d. Suitable X-ray-quality crystals of 1a,c−f, 2a, 3a,b2, and 4d were grown by slow evaporation of a dichloromethane/n-hexane solvent mixture in the temperature range +25 to −5 °C, and X-ray diffraction studies were undertaken. Relevant crystallographic data and details of measurements are given in Table S1 in the Supporting Information. X-ray crystallographic data were collected from their single crystals mounted on Oxford Diffraction XCALIBUR-S CCD and Agilent Technologies SuperNova systems equipped with graphitemonochromated Mo Kα radiation (0.71070 Å). The data were collected by the ω−2θ scan mode, and absorption correction was applied by using Multi-Scan. The structure was solved by direct methods (SHELXS-97) and refined by full-matrix least squares against F2 using SHELXL-97 software.42 Non-hydrogen atoms were refined with anisotropic thermal parameters, except C(12) of compound 1a. In 3a, a solvent-accessible void was observed, which was omitted by applying the SQUEEZE option from Platon. All hydrogen atoms were geometrically fixed and refined using a riding model. Crystallographic data for the structural analysis have been deposited with the Cambridge Crystallographic Data Centre: CCDC Nos. 795627, 795629, 795626, 795628, 938470, 795630, 938469, 938471, and 938472 for compounds 1a,c−f, 2a, 3a,b2, and 4d, respectively. Copies of this information may be obtained free of charge from The Director, CCDC, 12 Union Road, Cambridge CB2 1EZ, U.K (fax, +44 1223 336033; e-mail, [email protected]; web, http://www.ccdc.cam. ac.uk).

(CO), 196.8 (Ru-CO); MS (m/z, ES+) 1020 (M+). Anal. Calcd for C47H28Fe2O7Ru2: C, 55.42; H, 2.77. Found: C, 56.08; H, 2.86. Thermolysis of 1a−f with Pt(C2H4)(PPh3)2. In a typical reaction, a toluene (10 mL) solution containing [Pt(C2H4)(PPh3)2] (0.019 g, 0.025 mmol) and one of the compounds 1a−f (0.020 g, 0.02 mmol) was heated for 6 h at 100 °C. The progress of the reaction was continuously monitored on TLC plates at intervals of 2 h. After completion of the reaction the solvent was evaporated and the residue of each reaction mixture was subjected to chromatographic workup by TLC using a 20/80 elution mixture of dichloromethane and hexane, which afforded respective Ru2Pt clusters 3a−c and phosphinesubstituted derivatives 4a−f. 3a: yield 16 mg, 53%; IR (cm−1, νCO) 2058 (w), 2041 (w), 2016 (w), 1991 (w), 1972 (w); 1H NMR (CDCl3) δ 3.94 (s, 5 H, η5-C5H5), 4.34 (s, 5 H, η5-C5H5), 3.72−4.47 (m, 8H, η5-C5H4), 7.13−7.85 (m, 25H, C6H5); 13C NMR (CDCl3) δ 33.8, 139.3 (Pt-η2-CC), 93.4 (Ptη2-CCC), 31.9 (Ru-C), 114.1−133.4 (m, C6H5), 66.1−74.8 (m, η5-C5H4), 70.4 (s, η5-C5H5), 70.5 (s, η5-C5H5), 96.2, 96.7 (PhCC, PhCC), 123.4 (FcCC−), 103.9 (FcCC), 193.8, 195.1, 196.8 (M-CO); 31P NMR (CDCl3) δ −19.97 (1JPtP = 2963 Hz); MS (m/z, ES+) 1449 (M+). Anal. Calcd for C64H43Fe2O6PPtRu2: C, 53.00; H, 2.97. Found: C, 53.61; H, 3.32. 4a: yield 8 mg, 28%; IR (cm−1, νCO) 2052 (m), 1989 (m), 1965 (m); 1H NMR (CDCl3) δ 4.21 (s, 5H, η5-C5H5), 4.25 (s, 5H, η5C5H5), 4.20−4.88 (m, 8H, η5-C5H4), 7.30−7.38 (m, 25H, C6H5); 13C NMR (CDCl3) δ 128.2−134.5 (m, C6H5), 68.2−69.5 (m, η5-C5H4), 69.6 (s, η5-C5H5), 70.4 (s, η5-C5H5), 93.8−96.9 (m, PhCC, PhC C), 103.1−122.8 (m, C4Ru), 191.3 (Ru-CO); 31P NMR (CDCl3) δ 42.60; MS (m/z, ES+) 1226 (M+). Anal. Calcd for C63H43Fe2O5PRu2: C, 61.78; H, 3.54. Found: C, 62.46; H, 2.80. 3b1: yield 7 mg, 24%; IR (cm−1, νCO) 2061 (w), 2044 (m), 2018 (s), 1997 (m), 1977 (s); 1H NMR (CDCl3) δ 3.96 (s, 5 H, η5-C5H5), 4.42 (s, 5 H, η5-C5H5), 3.76−4.48 (m, 8H, η5-C5H4), 7.17−7.91 (m, 25H, C6H5); 13C NMR (CDCl3) δ 33.9, 140.1 (Pt-η2-CC), 85.1 (Ptη2-CCC), 32.7 (Ru-C), 113.7−132.7 (m, C6H5), 67.1−75.1 (m, η5-C5H4), 71.2 (s, η5-C5H5), 71.3 (s, η5-C5H5), 95.3, 96.4 (PhCC, PhCC), 123.4 (FcCC), 103.0 (FcCC), 195.8 (M-CO); 31P NMR (CDCl3) δ −19.62 (1JPtP = 2963 Hz); MS (m/z, ES+) 1449 (M+). Anal. Calcd for C64H43Fe2O6PPtRu2: C, 53.00; H, 2.97. Found: C, 53.46; H, 3.24. 3b2: yield 9 mg, 31%; IR (cm−1, νCO) 2060 (w), 2044 (m), 2018 (s), 1995 (m), 1976 (s); 1H NMR (CDCl3) δ 3.96 (s, 5 H, η5-C5H5), 4.42 (s, 5 H, η5-C5H5), 3.74−4.52 (m, 8H, η5-C5H4), 7.16−7.90 (m, 25H, C6H5); 13C NMR (CDCl3) δ 33.9, 140.1 (Pt-η2-CC), 85.8 (Ptη2-CCC), 32.6 (Ru-C), 113.7−132.6 (m, C6H5), 67.8−75.3 (m, η5-C5H4), 71.2 (s, η5-C5H5), 71.3 (s, η5-C5H5), 95.3, 96.4 (PhCC, PhCC), 123.4 (FcCC), 103.0 (FcCC), 195.9, 196.8 (M-CO); 31 P NMR (CDCl3) δ −19.62 (1JPtP = 2965 Hz); MS (m/z, ES+) 1449 (M+). Anal. Calcd for C64H43Fe2O6PPtRu2: C, 53.00; H, 2.97. Found: C, 52.62; H, 3.29. 4b: yield 5 mg, 21%; IR (cm−1, νCO) 2054 (s), 1991 (s), 1968 (w); 1 H NMR (CDCl3) δ 4.21 (s, 5H, η5-C5H5), 4.25 (s, 5H, η5-C5H5), 4.20−4.89 (m, 8H, η5-C5H4), 7.31−7.39 (m, 25H, C6H5); 13C NMR (CDCl3) δ 128.3−134.5 (m, C6H5), 68.3−69.6 (m, η5-C5H4), 69.4 (η5C5H5), 70.3 (s, η5-C5H5), 83.8−96.9(m, FcCC, FcCC, PhCC, PhCC), 103.0−123.4 (m, C4Ru), 192.1 (Ru-CO); 31P NMR (CDCl3) δ 42.69; MS (m/z, ES+) 1226 (M+). Anal. Calcd for C63H43Fe2O5PRu2: C, 61.78; H, 3.54. Found: C, 62.52; H, 3.60. 3c1: yield 8 mg, 27%; IR (cm−1, νCO) 2057 (m), 2042 (w), 2012 (m), 1992 (s), 1977 (m); 1H NMR (CDCl3) δ 3.98 (s, 5 H, η5-C5H5), 4.31 (s, 5 H, η5-C5H5), 3.81−4.42 (m, 8H, η5-C5H4), 7.13−7.83 (m, 25H, C6H5); 31P NMR (CDCl3) δ −20.01 (1JPtP = 2968 Hz); MS (m/ z, ES+) 1449 (M+) Anal. Calcd for C64H43Fe2O6PPtRu2: C, 53.00; H, 2.97. Found: C, 53.32; H, 3.19. 3c2: yield 10 mg, 32%; IR (cm−1, νCO) 2057 (m), 2042 (w), 2011 (m), 1991 (s), 1977 (m); 1H NMR (CDCl3) δ 3.98 (s, 5 H, η5-C5H5), 4.30 (s, 5 H, η5-C5H5), 3.81−4.43 (m, 8H, η5-C5H4), 7.13−7.83 (m, 25H, C6H5); 31P NMR (CDCl3) δ −20.01 (1JPtP = 2969 Hz); MS (m/ z, ES+) 1449 (M+) Anal. Calcd for C64H43Fe2O6PPtRu2: C, 53.00; H, 2.97. Found: C, 53.47; H, 3.21.

1

■

ASSOCIATED CONTENT

* Supporting Information S

Text, figures, a table, and CIF files giving a coupling illustration of FcCCCCPh, molecular structures of 1c−e and 4d, experimental details of thermal and photochemical reactions of FcCCCCPh with Ru3(CO)12, and crystallographic data and measurement details for 1a,c−f, 2a,3a,b2, and 4d. This material is available free of charge via the Internet at http:// pubs.acs.org.

■

AUTHOR INFORMATION

Corresponding Author

*E-mail for P.M.: [email protected]. Notes

The authors declare no competing financial interest. H


Organometallics

■

Article

Joshi, R. K.; Mobin, S. M. J. Organomet. Chem. 2012, 712, 7. (c) Mathur, P.; Singh, A. K.; Singh, V. K.; Singh, P.; Rahul, R.; Mobin, S. M.; Thöne, C. Organometallics 2005, 24, 4793. (d) Barrow, M.; Cromhout, N. L.; Cunningham, D.; Manning, A. R.; McArdle, P. J. Organomet. Chem. 2000, 612, 61. (e) Calderon, R.; Vahrenkamp, H. J. Organomet. Chem. 1998, 555, 113. (f) Snead, T. E.; Mirkin, C. A.; Lu, K. L.; Nguyen Son Binh, T.; Feng, W. C.; Bekman, H. L.; Geoffroy, G. L.; Rheingold, A. L.; Haggerty, B. S. Organometallics 1992, 11, 2613. (14) (a) Takao, T.; Suzuki, H. Coord. Chem. Rev. 2012, 256, 695. (b) Moriya, M.; Tahara, A.; Takao, T.; Suzuki, H. Eur. J. Inorg. Chem. 2009, 23, 3393. (c) Zhang, L.; Sung, H. H.-Y.; Williams, I. D.; Lin, Z.; Jia, G. Organometallics 2008, 27, 5122. (d) Takao, T.; Moriya, M.; Suzuki, H. Organometallics 2008, 27, 18. (e) Hill, A. F.; Rae, A. D.; Schultz, M.; Willis, A. C. Organometallics 2007, 26, 1325. (f) Yamamoto, Y.; Miyabe, M.; Itoh, K. Eur. J. Inorg. Chem. 2004, 3651. (15) (a) Yeh, W.-Y.; Shiue, T.-W.; Peng, S.-M.; Lee, G.-H. Organometallics 2003, 22, 2990. (b) Baya, M.; Esteruelas, M. A.; Onate, E. Organometallics 2001, 20, 4875. (c) Poe, A. J.; Moreno, C. Organometallics 1999, 18, 5518. (d) Koridze, A. A.; Astakhova, N. M.; Dolgushin, F. M.; Yanovsky, A. I.; Struchkov, Y. T.; Petrovskii, P. V. Organometallics 1995, 14, 2167. (16) (a) Singh, K.; McWhinnie, W. R.; Chen, H. L.; Sunb, M.; Hamor, T. A. J. Chem. Soc., Dalton Trans. 1996, 1545. (b) Huebener, P.; Weiss, E. J. Organomet. Chem. 1977, 129, 105. (17) (a) Aime, S.; Milone, L.; Tiripicchio, A.; Lanfredi, A. M. M. J. Chem. Soc., Dalton Trans. 1979, 1664. (b) Lokshin, B. V.; Ezernitskaya, M. G.; Zdanovich, V. I.; Koridze, A. A. J. Organomet. Chem. 1999, 580, 36. (18) (a) Tussupbayev, S.; Vyboishchikov, S. F. Organometallics 2009, 28, 3029. (b) Kawatsura, M.; Yamamoto, M.; Namioka, J.; Kajita, K.; Hirakawa, T.; Itoh, T. Org. Lett. 2011, 13, 1001. (c) Varela, J. A.; Castedo, L.; Saá, C. J. Org. Chem. 2003, 68, 8595. (d) Wesendrup, R.; Schwarz, H. Organometallics 1997, 16, 461. (e) Periasamy, M.; Mukkanti, A.; Raj, D. S. Organometallics 2004, 23, 6323. (19) (a) Gervasio, G.; Marabello, D.; Sappa, E.; Secco, A. J. Organomet. Chem. 2005, 690, 3755. (b) Anillo, A.; Diaz, M. R.; GarciaGranda, S.; Obeso-Rosete, R.; Galindo, A.; Ienco, A.; Mealli, C. Organometallics 2004, 23, 471. (c) Arce, A. J.; Arrojo, P.; Deeming, A. J.; De Sanctis, Y. J. Chem. Soc., Dalton Trans. 1992, 2423. (d) Arce, A. J.; Machado, R.; Rivas, C.; De Sanctis, Y.; Deeming, A. J. J. Organomet. Chem. 1991, 419, 63. (e) Ogilvy, A. E.; Draganjac, M.; Rauchfuss, T. B.; Wilson, S. R. Organometallics 1988, 7, 1171. (f) Casarin, M.; Ajo, D.; Vittadini, A.; Ellis, D. E.; Granozzi, G.; Bertoncello, R.; Osella, D. Inorg. Chem. 1987, 26, 2041. (g) Aime, S.; Occhiello, E. J. Chem. Soc., Dalton Trans. 1986, 1863. (h) Casarin, M.; Ajo, D.; Granozzi, G.; Tondello, E.; Aime, S. Inorg. Chem. 1985, 24, 1241. (20) (a) Mastrorilli, P. Eur. J. Inorg. Chem. 2008, 4835. (b) Albinati, A.; Leoni, P.; Marchetti, F.; Marchetti, L.; Pasquali, M.; Rizzato, S. Eur. J. Inorg. Chem. 2008, 4092. (c) Forniés, J.; Fortuño, C.; Ibáñez, S.; Martin, A. Inorg. Chem. 2008, 47, 5978. (d) Latronico, M.; Polini, F.; Gallo, V.; Mastrorilli, P.; Calmuschi-Cula, B.; Englert, U.; Re, N.; Repo, T.; Räisänen, M. Inorg. Chem. 2008, 47, 9779. (e) Mastrorilli, P. Dalton Trans. 2008, 4555. (21) Scoles, L.; Yamamoto, J. H.; Brissieux, L.; Sterenberg, B. T.; Udachin, K. A.; Carty, A. J. Inorg. Chem. 2001, 40, 6731. (22) (a) Cao, J.; Huangzab, X.; Wu, L. Chem. Commun. 2013, 49, 7747. (b) Chakravarty, A. R.; Cotton, F. A. Inorg. Chem. 1985, 24, 3584. (c) Bruce, M. I.; Humphrey, P. A.; Okucu, S.; Schmutzler, R.; Skelton, B. W.; White, A. H. Inorg. Chim. Acta 2004, 357, 1805. (d) Yeh, W.; Tsai, K. Organometallics 2010, 29, 604. (e) Gracia, C.; Marco, G.; Navarro, R.; Romero, P.; Soler, T.; Urriolabeitia, E. P. Organometallics 2003, 22, 4910. (f) Kabir, S. E.; Ahmed, F.; Ghosh, S.; Hassan, M. R.; Islam, M. S.; Sharmin, A.; Tocher, D. A.; Haworth, D. T.; Lindeman, S. V.; Siddiquee, T. A.; Bennett, D. W.; Hardcastle, K. I. J. Organomet. Chem. 2008, 693, 2657. (g) Keirn, W.; Behr, A.; Gruber, B.; Hoffrnann, B.; Kowaldt, F. H.; Kurschner, U.; Limbacker, B.; Sistig, F. P. Organometallics 1986, 5, 2356. (h) Kwong, F.; Lai, C.; Yu, M.;

ACKNOWLEDGMENTS P.M., D.K.R., and R.K.J. are grateful to the Department of Science and Technology, New Delhi, India, for financial support.

■

REFERENCES

(1) Shriver, D. F.; Kaesz, H. D.; Adams, R. D. The Chemistry of Cluster Complexes; VCH: Weinheim, Germany, 1990. (2) (a) Guczi, L.; Knozinger, H. Metal Clusters in Catalysis; Elsevier: Amsterdam, 1986. (b) Whyman, R. In Transition Metal Clusters; Johnson, B. F. G., Ed.; Wiley-Interscience: New York, 1980. (3) (a) Sinfelt, J. H. Bimetallic Catalysts. Discoveries, Concepts and Applications; Wiley: New York, 1983. (b) Sinfelt, J. H. Sci. Am. 1985, 253, 90. (c) Sinfelt, J. H. Acc. Chem. Res. 1977, 10, 15. (d) Sachtler, W. M. H. J. Mol. Catal. 1984, 25, 1. (e) Guczi, L. J. Mol. Catal. 1984, 25, 13. (f) Sachtler, W. M. H.; van Santen, R. A. Adv. Catal. 1977, 26, 69. (g) Ponec, V. Adv. Catal. 1983, 32, 149. (h) Biswas, J.; Bickle, G. M.; Gray, P. G.; Do, D. D.; Barbier, J. Catal. Rev.-Sci. Eng. 1988, 30, 161. (i) Diaz, G.; Garin, F.; Maire, G. J. Catal. 1983, 82, 13. (j) Braunstein, P.; Devenish, R.; Gallezot, P.; Heaton, B. T.; Humphreys, C. J.; Kervennal, J.; Mulley, S.; Ria, M. Angew. Chem., Int. Ed. Engl. 1988, 27, 927. (k) Adams, R. D.; Bamard, T. S.; Li, Z.; Wu, W.; Yamamoto, J. H. J. Am. Chem. Soc. 1994, 116, 9103. (4) (a) Simon, U.; Braustein, P.; Oro, L. A.; Raithby, P. R. Metal Clusters in Chemistry; Wiley-VCH: Weinheim, Germany, 1999; Vol. 3, p 1342. (b) Schmid, G.; Liu, Y.-P.; Schumann, M.; Raschke, T.; Radehaus, C. Nano Lett. 2001, 1, 405. (c) Hoeppener, S.; Chi, L.; Fuchs, H. Nano Lett. 2002, 2, 459. (d) Werts, M. H. V.; Lambert, M.; Bourgoin, J.-P.; Brust, M. Nano Lett. 2002, 2, 43. (e) Templeton, A. C.; Wuelfing, W. P.; Murray, R. W. Acc. Chem. Res. 2000, 33, 27. (f) Chi, L. F.; Hartig, M.; Drechsler, T.; Schwaack, T.; Seidel, C.; Fuchs, H.; Schmid, G. Appl. Phys. Lett. 1998, 66, S187. (g) Femoni, C.; Iapalucci, M. C.; Kaswalder, F.; Longoni, G.; Zacchini, S. Coord. Chem. Rev. 2006, 250, 1580. (5) (a) Bruce, M. I.; Low, P. J.; Werth, A.; Skelton, B. W.; White, A. H. J. Chem. Soc., Dalton Trans. 1996, 1551. (b) Clarke, L. P.; Davies, J. E.; Raithby, P. R.; Shields, G. P. J. Chem. Soc., Dalton Trans. 2000, 4527. (c) Cabeza, J. A.; Grepioni, F.; Moreno, M.; Riera, V. Organometallics 2000, 19, 5424. (d) Lau, C. S.-W.; Wong, W.-T. J. Chem. Soc., Dalton Trans. 1999, 2511. (e) Adams, R. D.; Kwon, O.-S.; Qu, B.; Smith, M. D. Organometallics 2001, 20, 5225. (f) Deeming, A. J.; Felix, M. S. B.; Bates, P. A.; Hursthouse, M. B. J. Chem. Soc., Chem. Commun. 1987, 461. (6) Astier, A.; Daran, J.-C.; Jeannin, Y.; Rigault, C. J. Organomet. Chem. 1983, 241, 53. (7) (a) Bruce, M. I.; Matisons, J. G.; Skelton, B. W.; White, A. H. J. Organomet. Chem. 1983, 251, 249. (b) Mathur, P.; Avasare, V. D.; Mobin, S. M. J. Cluster Sci. 2009, 20, 399. (c) Mathur, P.; Ji, R. S.; Boodida, S.; Singh, A. K.; Mobin, S. M. J. Organomet. Chem. 2010, 695, 196. (8) (a) Bruce, M. I.; Zaitseva, N. N.; Skelton, B. W.; White, A. H. Inorg. Chim. Acta 1996, 250, 129. (b) Mathur, P.; Das, A.; Chatterjee, S.; Mobin, S. M. J. Organomet. Chem. 2008, 693, 1919. (9) (a) Arnanz, A.; Moreno, C.; Marcos, M.-L.; González-Velasco, J.; Pastor, C.; Medina, R. M.; Macazaga, M.-J. Organometallics 2011, 30, 1838. (b) Adams, R. D.; Qu, B. Organometallics 2000, 19, 2411. (c) Adams, R. D.; Qu, B. Organometallics 2001, 19, 4090. (10) Karpov, M. G.; Tunik, S. P.; Denisov, V. R.; Starova, G. L.; Nikol’skii, A. B.; Dolgushin, F. M.; Yanovsky, A. I.; Struchkov, Y. T. J. Organomet. Chem. 1995, 485, 219. (11) (a) Brayshaw, S. K.; Clarke, L. P.; Homanen, P.; Koentjoro, O. F.; Warren, J. F.; Raithby, P. R. Organometallics 2011, 30, 3955. (b) Tunik, S. P.; Khripun, V. D.; Balova, I. A.; Nordlander, E.; Haukka, M.; Pakkanen, T. A.; Raithby, P. R. Organometallics 2001, 20, 3854. (12) Bruce, M. I.; Skelton, B. W.; White, A. H.; Zaitseva, N. N. Inorg. Chem. Commun. 1998, 1, 134. (13) (a) Mathur, P.; Tauqeer, M.; Ji, R. S.; Lahiri, G. K.; Mobin, S. M. RSC Adv. 2014, 4, 6878. (b) Mathur, P.; Jha, B.; Raghuvanshi, A.; I


Organometallics

Article

Tian, Y.; Chan, K. Tetrahedron 2003, 59, 10295. (i) Kwong, F.; Chan, K. Organometallics 2000, 19, 2058. (23) Koridze, A. A.; Zdanovich, V. I.; Andrievskaya, N. V.; Siromakhova, Y.; Petrovskii, P. V.; Ezernitskaya, M. G.; Dolgushin, F. M.; Yanovsky, A. I.; Struchkov, Y. T. Russ. Chem. Bull. 1996, 45, 1200. (24) Horikoshia, S.; Osawaa, A.; Sakamotoa, S.; Serponeb, N. Appl. Catal., A 2013, 460−461, 52. (25) (a) Antiñolo, A.; Carrillo-Hermosilla, F.; Cadierno, V.; Garcı ́aÁ lvarez, J.; Otero, A. ChemCatChem 2012, 4, 123. (b) Yamada, S.; Takasu, A.; Kawamura, K. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3732. (c) Al-Masum, M.; Welch, R. L. Tetrahedron Lett. 2014, 55, 1726. (d) Ribeiro, S. R.; Raminelli, C.; Porto, A. L. M. J. Fluorine Chem. 2013, 154, 53. (26) (a) Brown, T. L.; Zhang, S. Inorg. Chem. 1995, 34, 1164. (b) Cotton, F. A. Prog. Inorg. Chem. 1976, 21, 1. (c) Jemmis, E. D.; Pinhas, A. R.; Hoffmann, R. J. Am. Chem. Soc. 1980, 102, 2576. (27) (a) Alvarez, M. A.; Garcı ́a, M. E.; Garcı ́a-Vivó, D.; Menéndez, S.; Ruiz, M. A. Organometallics 2013, 32, 218. (b) Muratsugu, S.; Sodeyama, K.; Kitamura, F.; Sugimoto, M.; Tsuneyuki, S.; Miyashita, S.; Kato, T.; Nishihara, H. J. Am. Chem. Soc. 2009, 131, 1388. (28) (a) Rahaman, A.; Ghosh, S.; Unwin, D. G.; Modi, S. B.; Holt, K. B.; Kabir, S. E.; Nordlander, E.; Richmond, M. G.; Hogarth, G. Organometallics 2014, 33, 1356. (b) Georgakaki, I. P.; Thomson, L. M.; Lyon, E. J.; Hall, M. B.; Darensbourg, M. Y. Coord. Chem. Rev. 2003, 238−239, 255. (c) Evans, D. J.; Pickett, C. J. Chem. Soc. Rev. 2003, 32, 268. (d) Rauchfuss, T. B. Inorg. Chem. 2004, 43, 14. (e) Sun, L.; Åkermark, B.; Ott, S. Coord. Chem. Rev. 2005, 249, 1653. (f) Liu, X.; Ibrahim, S. K.; Tard, C.; Pickett, C. J. Coord. Chem. Rev. 2005, 249, 1641. (g) Liu, T.; Darensbourg, M. Y. J. Am. Chem. Soc. 2007, 129, 7008. (h) Justice, A. K.; Rauchfuss, T. B.; Wilson, S. R. Angew. Chem., Int. Ed. 2007, 46, 6152. (i) Thomas, C. M.; Liu, T.; Hall, M. B.; Darensbourg, M. Y. Chem. Commun. 2008, 1563. (j) Thomas, C. M.; Darensbourg, M. Y.; Hall, M. B. J. Inorg. Biochem. 2007, 101, 1752. (29) (a) Capon, J. F.; Gloaguen, F.; Pétillon, F. Y.; Schollhammer, P.; Talarmin, J. Eur. J. Inorg. Chem. 2008, 4671. (b) Wang, W.; Rauchfuss, T. B.; Zhu, L. J. Am. Chem. Soc. 2014, 136, 5773. (c) Wang, W.; Rauchfuss, T. B.; Moore, C. E.; Rheingold, A. L.; Gioia, L. D.; Zampella, G. Chem. Eur. J. 2013, 19, 15476. (d) Zaffaroni, R.; Rauchfuss, T. B.; Fuller, A. Organometallics 2013, 32, 232. (30) (a) Blosser, P. W.; Schimpff, D. G.; Gallucci, J. C.; Wojcicki, A. Organometallics 1993, 12, 1993. (b) Lentz, D.; Nickelt, N.; Willemsen, S. Chem. Eur. J. 2002, 8, 1205. (31) Adams, R. D.; Li, Z.; Wu, W.; Yamamoto, J. Organometallics 1994, 13, 2357. (32) Adams, R. D.; Bunz, U.; Captain, B.; Fu, W.; Steffen, W. J. Organomet. Chem. 2000, 614, 75. (33) Willocq, C.; Vidick, D.; Tinant, B.; Delcorte, A.; Bertrand, P.; Devillers, M.; Hermans, S. Eur. J. Inorg. Chem. 2011, 4721. (34) Yasuoka, N.; Morita, M.; Kai, Y.; Kasai, N. J. Organomet. Chem. 1975, 90, 111. (35) Kadonaga, M.; Yasuoka, N.; Kasai, Y. J. Chem. Soc., Chem. Commun. 1971, 1597. (36) Lugan, N.; Bonnet, J.-J.; Ibers, J. A. J. Am. Chem. Soc. 1985, 107, 4484. (37) (a) Bruce, M. I.; Humphrey, P. A.; Skelton, B. W.; White, A. H. J. Organomet. Chem. 1996, 526, 85. (b) Bruce, M. I.; Humphrey, P. A.; Skelton, B. W.; White, A. H. J. Organomet. Chem. 1997, 539, 141. (38) (a) Bruce, M. I.; Humphrey, P. A.; Skelton, B. W.; White, A. H.; Costuas, K.; Halet, J.-F. J. Chem. Soc., Dalton Trans. 1999, 479. (b) Bruce, M. I.; Skelton, B. W.; White, A. H.; Zaitseva, N. N. Inorg. Chem. Commun. 1999, 2, 17. (39) (a) Bender, R.; Okio, C.; Welter, R.; Braunstein, P. Dalton Trans. 2009, 4901. (b) Bennett, M. A.; Berry, D. E.; Dirnberger, T.; Hockless, D. C. R.; Wenger, E. J. Chem. Soc., Dalton Trans. 1998, 2367. (40) (a) Uddin, M. N.; Mottalib, M. A.; Begum, N.; Ghosh, S.; Raha, A. K.; Haworth, D. T.; Lindeman, S. V.; Siddiquee, T. A.; Bennett, D. W.; Hogarth, G.; Nordlander, E.; Kabir, S. E. Organometallics 2009, 28, 1514. (b) Beck, W.; Keubler, M.; Leidl, E.; Nagel, U.; Schaal, M. J.

Chem. Soc., Chem. Commun. 1981, 446. (c) Yeh, W.; Tsai, K. Organometallics 2010, 29, 60. (41) (a) Frauhiger, B. E.; Templeton, J. L. Organometallics 2012, 31, 2770. (b) Kostelansky, C. N.; MacDonald, M. G.; White, P. S.; Templeton, J. L. Organometallics 2006, 25, 2993. (c) West, N. M.; Reinartz, S.; White, P. S.; Templeton, J. L. J. Am. Chem. Soc. 2006, 128, 2059. (d) MacDonald, M. G.; Kostelansky, C. N.; White, P. S.; Templeton, J. L. Organometallics 2006, 25, 4560. (e) Engelman, K. L.; White, P. S.; Templeton, J. L. Inorg. Chim. Acta 2009, 362, 4461. (f) Engelman, K. L.; White, P. S.; Templeton, J. L. Organometallics 2010, 29, 4943. (42) Sheldrick, G. M. Acta Crystallogr., Sect. A 2008, A64, 112.

J


Synthesis of Novel Allene-Coordinated, Phosphido-Bridged Ru2Pt

Recommend Documents