Oxidative Addition of Diphenyldichalcogenides PhEEPh - American

Jan 3, 2013 - Roman Jambor, ... 10, Pardubice, Czech Republic ... of Microbiology, Academy of Sciences of the Czech Republic, Vνdeňská 1083, CZ-142...
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Oxidative Addition of Diphenyldichalcogenides PhEEPh (E = S, Se, Te) to Low-Valent CN- and NCN-Chelated Organoantimony and Organobismuth Compounds Petr Šimon,†,‡ Roman Jambor,† Aleš Růzǐ čka,† and Libor Dostál*,† †

Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, CZ-532 10, Pardubice, Czech Republic ‡ Laboratory of Biotransformation, Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídeňská 1083, CZ-142 20 Prague, Czech Republic S Supporting Information *

ABSTRACT: The reactions of the organoantimony(I) compound L14Sb4 (1) (where L1 = [o-C6H4(CHNC6H3(i-Pr)2-2,6)]) with diphenyldichalcogenides PhEEPh (E = S, Se, or Te) gave compounds L1Sb(EPh)2 (E = S (2), Se (3), Te (4)) as the result of the oxidative addition of the antimony(I) atom across the chalcogen−chalcogen bond. The reaction of diphenyldichalcogenides PhEEPh with an in situ prepared organobismuth(I) compound (via reaction of the parent chloride L1BiCl2 (5) with two equivalents of K[B(s-Bu)3H]) gave surprisingly diorganobismuth compounds L12Bi(EPh) (E = S (6), Se (7), Te (8)) as the major products along with only a trace amount of the intended compounds L1Bi(EPh)2 (E = S (9), Se (10), Te (11)). It turned out that this is the result of instability of 9−11 in solution, and their decomposition provided compounds 6−8. The bismuth compounds containing the pincer-type ligand L2 (L2 = [o,o-C6H3(CH2NMe2)2]) containing an extra donor pendant arm were studied with the aim to support their stability by an additional N→Bi interaction. Thus, in situ preparation of the organobismuth(I) compound from L2BiCl2 (12) and two equivalents of K[B(s-Bu)3H] followed by the addition of PhEEPh gave compounds L2Bi(EPh)2 (E = S (13), Se (14), Te (15)). Compounds 13−15 showed no tendency for redistribution reaction, contrary to 9−11, due to the rigid coordination of both nitrogen donor atoms of the ligand L2 to the bismuth atom. All studied compounds were characterized by the help of 1H and 13C NMR spectroscopy, by elemental analysis, and except compounds 4, 14, and 15 by single-crystal X-ray diffraction analyses.



approximate η2:η3 manner. Another landmark magnesium(I) compound, reporter by Jones,6 is now often used as an excellent reducing reagent.7 By analogy, we have also demonstrated that the low-valent tin(I) and antimony(I) compounds stabilized by the NCN pincer-type coordinating ligands are able to activate elemental chalcogens under formation of molecular chalcogenides.8 In the course of this investigation, unprecedented compounds were isolated and characterized by single-crystal X-ray diffraction analyses, and some interesting examples are summarized in Chart 1.8 We now wonder if also diphenyldichalcogenides PhEEPh (E = S, Se, Te) can be activated in a similar manner as elemental chalcogens (Chart 1),8 giving molecular antimony(bismuth)phenylchalcogenolates RM(EPh)2 (M = Sb, Bi). Although some reactions leading to such compounds were studied in the past, they are noticeably restricted to sulfur species.9 The number of structurally characterized heavier analogues is rather limited. The examples include only three bismuth compounds,

INTRODUCTION Recently, we and others have demonstrated that various CN or NCN chelating ligands can be used with success for the stabilization of various compounds of heavier main group elements, in particular tin, antimony, and bismuth derivatives.1 Utilization of such chelating ligands allowed stabilization of a variety of low-valent compounds1 including the first examples of monomeric stibinidene and bismuthinidene2 and distannyne containing a single bond between tin atoms.3 In this way, these chelating ligands represent an attractive alternative to the sterically demanding ligands that are commonly used for stabilization of low-valent main group metal compounds. These compounds have often interesting and unprecedented reactivity similar to transition metal compounds, and their properties have been continuously studied and reviewed.4 Many compounds containing the central atom in an unusual lowvalent oxidation state also have strongly reducing properties as recently nicely outlined for example by Power et al.5 They reported on the reaction of cyclooctatetraene (cot) with terphenyl-substituted distannyne, giving an inverse sandwich structure, where the cot2− ring bridges two Sn atoms in an © 2013 American Chemical Society

Received: November 1, 2012 Published: January 3, 2013 239

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Chart 1

Scheme 2. Synthesis of 5−8

[(Me3Si)2CH]Bi(TeSiMe3)2,10 Ph2BiSePh, and (RSe)3Bi (where R is 2-(4,4-dimethyloxazolino)phenyl).11 This fact also correlates with a rather low number of examples of analogous molecular organoantimony and organobismuth selenides and tellurides.8a,12 We report herein on the oxidative addition of diphenyldichalcogenides PhEEPh (E = S, Se, Te) to low-valent organoantimony(I) and, in situ prepared, organobismuth(I) compounds containing both the CN chelating ligand L1 and the NCN pincer-type ligand L2 (where L1 = [o-C6H4(CH NC6H3(i-Pr)2-2,6)] and L2 = [o,o-C6H3(CH2NMe2)2], Chart 2). These reactions afforded molecular phenyl chalcogenolates

Scheme 3. Synthesis of 9−11

Chart 2

(Schemes 1−4), which were characterized with the help of 1H and 13C NMR spectroscopy, by elemental analysis, and for the majority of compounds by single-crystal X-ray diffraction analyses. Scheme 4. Synthesis of 13−15

Scheme 1. Synthesis of 2−4

solvents and moderately soluble in hexane. Noteworthy, compound 4 slowly decomposes in solution back to the starting compounds 1 and PhTeTePh. The latter preferably crystallizes from the solution and was characterized several times by the help of single-crystal X-ray diffraction analyses during attempts to grow single crystals of 4 at low temperatures. Compounds 2−4 have satisfactory elemental analyses. The 1H and 13C NMR spectra in C6D6 of 2−4 contained in all cases only one set of signals for aromatic protons of L1 and EPh groups as well as for protons of the i-Pr groups and CHN moiety. Single crystals of 2 and 3 were obtained by crystallization from a toluene−hexane mixture at −30 °C, crystallographic data are given in Table S1, and molecular structures of 2 and 3



RESULTS AND DISCUSSION The organoantimony(I) compound L14Sb4 (1) has been synthesized according to the literature procedure.13 The reaction of 1 with diphenyldichalcogenides PhEEPh (E = S, Se) in toluene or benzene (for E = Te) gave the desired products L1Sb(EPh)2 (E = S (2), Se (3), Te (4)) (Scheme 1) as yellow (2, 3) and orange-red (4) solids. All prepared compounds 2−4 are stable for a long time in an inert atmosphere in the solid state and are well soluble in aromatic 240

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∑cov(Sb, S) = 2.43 Å14 and are also comparable to those found in the related antimony(III) phenylsulfides such as Ph2Sb(S-2,6-Me2C6H3) (2.438 Å),9g [Ph2Sb(SPh)]3Mo(CO)3 (2.429−2.436 Å),9f and (Mes)Sb(o-S-NC5H4)2 (2.490 and 2.509 Å).15 The coordination polyhedron of the central atom is a distorted ψ-trigonal bipyramid, where the atoms N(1) and S(2) occupy the axial positions (the bonding angle N(1)− Sb(1)−S(2) is 161.86(9)°) and the C(1), S(1) atoms together with the lone pair lie in equatorial positions. The molecular structure of 3 showed that the primary coordination sphere around the central antimony atoms Sb(1) and Sb(2) in 3 may be described analogously to 2 as a distorted ψ-trigonal bipyramid as a result of chelating coordination of the ligand L1 with the bond distances Sb(1)−N(1) 2.662(3) Å and Sb(2)−N(2) 2.724(3) Å. The range of the primary Sb−Se bond distances is 2.5779(6)−2.6537(6) Å, and all values correspond well to the ∑cov(Sb, Se) = 2.56 Å.14 In contrast to monomeric 2, weak intermolecular Sb−Se contacts are found in the structure of 3. The values of bond lengths Sb(1)−Se(4) and Sb(2)−Se(2) are 3.6902(6) and 3.6882(6) Å, respectively, slightly shorter than the ∑vdW(Sb, Se) = 3.90 Å. The lone pairs of the central antimony atoms are located in trans position to the respective ipso-carbon atoms of the ligand L1. There is no example of a structurally characterized antimony(III) phenylselenide for comparison. The organobismuth precursor L1BiCl2 (5) was prepared by the reaction of organolithium compound L1Li and BiCl3 in 1:1 molar ratio (Scheme 2). Compound 5 was observed after workup in a reasonable yield of 65% as an air-stable yellowish solid. The 1H and 13C NMR spectra contained only one set of signals in both aromatic and aliphatic regions. The signals of the methyl moieties of the flanking i-Pr groups are observed as two doublets in the 1H NMR spectrum, and similarly two signals are observed in the corresponding 13C NMR spectrum, which is indicative for the presence of a rigid N→Bi intramolecular interaction in CDCl3 solution. The molecular structure of 5 was unambiguously established by the X-ray

are depicted in Figures 1 and 2 together with relevant structural parameters summarized in the figure captions.

Figure 1. ORTEP plot of a molecule of 2. Hydrogen atoms are omitted for clarity. Selected bond lengths (Å) and angles (deg): Sb(1)−C(1) 2.168(4), Sb(1)−N(1) 2.672(3), Sb(1)−S(1) 2.4291(3), Sb(1)−S(2) 2.4871(16), N(1)−Sb(1)−S(2) 161.86(9), C(1)− Sb(1)−S(1) 91.99(10).

Compound 2 is monomeric in the solid state without significant intermolecular contacts. The central antimony atom is coordinated by the nitrogen donor atom of the ligand L1, and the Sb(1)−N(1) bond distance of 2.672(3) Å indicates the presence of an intramolecular interaction, when compared with ∑cov(Sb, N) = 2.11 Å and ∑vdW(Sb, N) = 3.55 Å, respectively.14 The Sb(1)−S(1) and Sb(1)−S(2) bond lengths are 2.4291(3) and 2.4871(16) Å, respectively. The second bond is slightly elongated, reflecting the trans position of the N(1) atom. Nevertheless, these values well coincide with the

Figure 2. ORTEP plot of a molecule of 3. Hydrogen atoms are omitted for clarity. Selected bond lengths (Å) and angles (deg): Sb(1)−N(1) 2.662(3), Sb(1)−Se(1) 2.5779(6), Sb(1)−Se(2) 2.6537(6), Sb(2)−N(2) 2.724(3), Sb(2)−Se(3) 2.5870(6), Sb(2)−Se(4) 2.6521(6), Sb(1)−Se(4) 3.6902(6), Sb(2)−Se(2) 3.6882(6), N(1)−Sb(1)−Se(2) 163.97(7), N(1)−Sb(1)−Se(1) 86.16(7), Se(1)−Sb(1)−Se(4) 171.41(2), Se(2)−Sb(1)− Se(3) 171.63(2), N(2)−Sb(2)−Se(4) 162.53(7), N(2)−Sb(2)−Se(3) 85.27(7). 241

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= 2.50 Å.14 The coordination polyhedron around each bismuth atom (Bi(1) and Bi(2)) is best described as a distorted square pyramid due to the chelating coordination of the ligand L1 (bond lengths Bi(1)−N(1) 2.491(7) and Bi(2)−N(2) 2.479(7) Å, compared with the ∑vdW(Bi, N) = 3.55 Å and the ∑cov(Bi, N) = 2.22 Å).14 The ipso-carbon atoms are located in the apical positions, and the nitrogen atom and three chlorine atoms occupy the basal positions; both pyramids share one of their edges (atoms Cl(1) and Cl(2)). The central Bi2Cl2 ring is strongly puckered, which may be ascribed to the syn position of both ligands L1 and both lone pairs of the central atoms on this ring. This type of coordination is quite unusual, because similar dimeric organobismuth systems containing one NC chelating ligand prefer an anti environment of the ligands with an essentially planar central Bi2Cl2 ring.16 The reaction of 5 with two equivalents of K[B(s-Bu)3H] in THF produced a deep violet solution, and hydrogen gas evolution indicating reduction of the central bismuth atom was clearly visible, analogously to the synthesis of the antimony(I) compound 1.13 Unfortunately, the product L1Bi17 is unstable at ambient temperature and decomposes with deposition of elemental bismuth metal. Our numerous attempts to isolate and characterize this low-valent bismuth precursor even at low temperatures failed until now. Nevertheless, the in situ prepared L1Bi precursor reacts smoothly with diphenyldichalcogenides PhEEPh (Scheme 2). Surprisingly, these reactions gave after 24 h diorganobismuth compounds L12Bi(EPh) (E = S (6), Se (7), Te (8)) in moderate yields. Compounds 6−8 were isolated as yellow (6, 7) and orange-red (8) solids, which are stable as solid samples for a long time in an inert atmosphere. The 1H and 13C NMR spectra of 6−8 in C6D6 contained in all cases only one set of signals for aromatic protons of L1 and EPh

diffraction analysis and is shown together with relevant structural parameters in Figure 3.

Figure 3. ORTEP plot of a molecule of 5. Hydrogen atoms and solvent (CH2Cl2) molecule were omitted for clarity. Selected bond lengths (Å) and angles (deg): Bi(1)−C(1) 2.219(9), Bi(1)−N(1) 2.491(7), Bi(1)−Cl(1) 2.680(2), Bi(1)−Cl(2) 3.048(2), Bi(1)−Cl(4) 2.532(2), Bi(2)−C(20) 2.238(9), Bi(2)−N(2) 2.4779(7), Bi(2)− Cl(3) 2.530(2), Bi(2)−Cl(2) 2.711(2), Bi(2)−Cl(1) 3.024(2), N(1)− Bi(1)−Cl(1) 162.21(16), Cl(2)−Bi(1)−Cl(4) 170.45(7), N(2)− Bi(2)−Cl(2) 163.18(16), Cl(1)−Bi(2)−Cl(3) 170.70(7), Bi(1)− Cl(1)−Bi(2) 93.78(7), Bi(1)−Cl(2)−Bi(2) 92.62(6).

Compound 5 forms a dimer in the solid state due to the significant Bi−Cl intermolecular contacts. The corresponding bond lengths Bi(1)−Cl(2) and Bi(2)−Cl(1) are 3.048(2) and 3.024(2) Å, respectively, and are significantly shorter than the ∑vdW(Bi, Cl) = 3.75 Å. The remaining Bi−Cl bond distances are in the range 2.530(2)−2.711(2) Å, close to the ∑cov(Bi, Cl)

Figure 4. ORTEP plot of molecules of 6−8. Hydrogen atoms are omitted for clarity. Selected bond lengths (Å) and angles (deg): For 6 (E = S): Bi(1)−N(1) 2.794(4), Bi(1)−N(2) 3.023(3), Bi(1)−C(1) 2.280(4), Bi(1)−C(20) 2.280(4), Bi(1)−S(1) 2.6154(11), N(1)−Bi(1)−S(1) 157.35(7), C(1)−Bi(1)−N(2) 157.04(11). For 7 (E = Se): Bi(1)−N(1) 2.801(6), Bi(1)−N(2) 3.029(5), Bi(1)−C(1) 2.293(6), Bi(1)−C(20) 2.266(5), Bi(1)−Se(1) 2.7261(8), N(1)−Bi(1)−Se(1) 157.17(10), C(1)−Bi(1)−N(2) 156.97(16). For 8 (E = Te): Bi(1)−N(1) 2.824(4), Bi(1)− N(2) 3.045(4), Bi(1)−C(1) 2.297(4), Bi(1)−C(20) 2.283(4), Bi(1)−Te(1) 2.9084(4), N(1)−Bi(1)−Te(1) 156.74(7), C(1)−Bi(1)−N(2) 157.24(12). 242

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Figure 5. ORTEP plot of a molecule of 10. Hydrogen atoms are omitted for clarity. Selected bond lengths (Å) and angles (deg): Bi(1)−N(1) 2.769(7), Bi(1)−Se(1) 2.7541(9), Bi(1)−Se(2) 2.6917(10), Bi(2)−N(2) 2.701(7), Bi(2)−Se(3) 2.7557(9), Bi(2)−Se(4) 2.6798(11), Bi(1)−Se(3) 3.5095(10), Bi(2)−Se(1) 3.5521(10), N(1)−Bi(1)−Se(1) 160.76(14), Se(2)−Bi(1)−Se(3) 172.12(3), N(2)−Bi(2)−Se(3) 162.44(14), Se(4)− Bi(2)−Se(1) 172.06(3), Bi(1)−Se(1)−Bi(2) 97.55(3), Bi(1)−Se(3)−Bi(2) 98.51(3).

Figure 6. ORTEP plot of a molecule of 11. Hydrogen atoms are omitted for clarity. Selected bond lengths (Å) and angles (deg): Symmetry operator a = 1/2−x, 1/2−y, −z. Bi(1)−N(1) 2.810(3), Bi(1)−Te(1) 2.8949(3), Bi(1)−Te(2) 2.9545(3), Bi(1)-Te(2a) 3.8642(3), N(1)−Bi(1)−Te(2) 161.57(7), Te(1)−Bi(1)−Te(2a) 174.81(1), Bi(1)−Te(1)−Bi(1a) 99.08(1).

groups as well as for protons of the i-Pr groups and CHN moiety. This indicates equivalence of both ligands L1 in solution, which may be ascribed to the fast fluxional coordination/decoordination procedure involving both nitrogen-containing pendant arms in solution. Similar behavior has been recently observed also for the related compound L12BiCl and other related doubly CN-chelated antimony and bismuth systems.18 The molecular structures of 6−8 were determined using single-crystal X-ray diffraction analyses and are illustrated together with corresponding structural parameters in Figure 4. The molecular structures of 6−8 are similar. All compounds remain essentially monomeric in the solids state without any remarkable intermolecular contact. Both nitrogen donor atoms are coordinated to the central bismuth atoms in 6−8, although

one of these interactions is significantly stronger than the second one, as established by the bond lengths Bi(1)−N(1) 2.794(4) and Bi(1)−N(2) 3.023(3) Å in 6, Bi(1)−N(1) 2.801(6) and Bi(1)−N(2) 3.029(5) Å in 7, and Bi(1)−N(1) 2.824(4) and 3.045(4) Å Bi(1)−N(2) in 8, compared with the ∑vdW(Bi, N) = 3.55 Å and the ∑cov(Bi, N) = 2.22 Å.14 The EPh group is bonded to the central bismuth atoms through a covalent bond, as demonstrated by the bond lengths Bi(1)− S(1) 2.6154(11) Å in 6, Bi(1)−Se(1) 2.7261(8) Å in 7, and Bi(1)−Te(1) 2.9084(4) Å in 8, which all well coincide with the ∑cov(Bi, E) = 2.53 (E = S), 2.67 (E = Se), and 2.87 Å (E = Te).14 The Bi−S bond distance in 6 resembles those found in related sulfur-containing organobismuth compounds such as Bi(SPh)3 (2.552−2.582 Å),19 PhBi(SC6F5)2(4-MeNC5H4) (2.627−2.818 Å),9b Ph2Bi(SPh) (2.588 Å),9c and Ph2Bi(S-2,6243

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Me2C6H3) (2.544 Å).9c Compounds Ph2Bi(SePh)11a and (RSe)3Bi11b (where R is 2-(4,4-dimethyloxazolino)phenyl) represent the only structurally characterized heavier analogues (the range of Bi−Se bond distances is 2.6910−2.7454 Å and is thus comparable to that found in 7). On the contrary, corresponding tellurium compounds are, to the best of our knowledge, unknown. The coordination polyhedron of the bismuth atom in 6−8, if taking both N→Bi interactions into account, can be described as a strongly distorted square pyramid with the ipso-carbon atom (C(20)) of one of the ligands located in the apical position and two nitrogen atoms, a chalcogen atom, and the second ipso-carbon atom (C(1)) occupying basal positions. The lone pair of the central atom is orientated in trans position to the ipso-carbon atom C(20). As the formation of 6−8 was unexpected, these reactions were studied in more detail. It turned out that significant shortening of the reaction time provided a mixture of products, where 6−8 are obtained as major products, but also evidence for the formation of the monoorganobismuth compounds L1Bi(EPh)2 (E = S (9), Se (10), Te (11)) was observed. Compounds 9 and 11 could be isolated in rather low yield (Scheme 3). However in the case of 10, only several orange single crystals of 10 were obtained along with the compound 7 as the major product. The single crystals of 10 were manually separated, and their composition was unambiguously determined using single-crystal X-ray diffraction analysis, but further characterization was not possible. The 1H NMR spectra of 9 and 11 in C6D6 contained only one expected set of signals for both L1 and EPh groups. Interestingly, measurement of the 1H NMR spectra of 9 after prolonged time in solution (several days) showed complete transformation of monorganobismuth compound 9 to the diorganobismuth derivative 6.20 Importantly, Bi(SPh)3 was detected in this mixture as a byproduct with the help of 1H NMR spectroscopy, and observed data are consistent with the published ones.19 This fact may be indicative of low stability of 9−11 in solution. Thus, 9−11 are most probably formed in the early stages of reaction between the bismuth(I) precursor and diphenyldichalcogenides, but then they readily convert to 6−8 (Scheme 3). While compounds 6−8 remain monomeric in the solid state, the common feature of all monoorganobismuth compounds 9− 11 is the presence of significant bismuth−chalcogen intermolecular contacts, which lead to formation of weakly bonded dimers with the central Bi2E2 four-membered rings (Figures S1, 5, and 6). These intermolecular contacts are characterized by the bond distances Bi(1)−S(4) 3.4513(18) and Bi(2)−S(2) 3.4895(17) Å in 9, Bi(1)−Se(3) 3.5059(10) and Bi(2)−Se(1) 3.5521(10) Å in 10, and Bi(1)−Te(2a) 3.8642(3) Å in 11. All these values are on the border of the ∑vdW(Bi, E) = 3.80 (E = S), 3.90 (E = Se), and 4.06 Å (E = Te) and indicate weak contacts. The bond lengths of the primary Bi−E bonds well correspond to the values expected for respective covalent bonds, the range of bond lengths being Bi− S 2.5591(18)−2.6430(17) Å in 9, Bi−Se 2.6798(11)− 2.7557(9) Å in 10, and Bi−Te 2.8949(3)−2.9545(3) Å in 11; ∑cov(Bi, E) = 2.54 (E = S), 2.67 (E = Se) and 2.87 Å (E = Te).14 The ligand L1 is coordinated to the central bismuth atom in a bidentate fashion in 9−11, where the N→Bi intramolecular interactions are characterized by the bond lengths Bi(1)−N(1) 2.745 and Bi(2)−N(2) 2.718(5) Å in 9, Bi(1)−N(1) 2.769(7) and Bi(2)−N(2) 2.701(7) Å in 10, and Bi(1)−N(1) 2.810(3) Å in 11, which are significantly shorter than the ∑vdW(Bi, N) =

3.55 Å.14 The coordination polyhedron around each bismuth atom in 9−11, taking into account both primary and secondary Bi−E bonds, is best described as a distorted square pyramid due to the chelating coordination of the ligand L1. The ipso-carbon atoms are located in the apical positions, and the nitrogen atom and three chalcogen atoms occupy the basal positions, both pyramids sharing one of their edges formed by two chalcogen atoms. The lone pairs of the central bismuth atoms are located in trans position to the ipso-carbon atoms. As monorganobismuth compounds of the type L1Bi(EPh)2 9−11 were shown to be unstable in solution, we decided to prepare similar bismuth compounds containing a pincer-type ligand L2, which holds the potential to stabilize the central bismuth atom by two N→Bi intramolecular interactions. Thus, the reactivity of NCN-chelated bismuth compound L2BiCl2 12 was studied in the same manner as in the case of the CNchelated analogue 5. The reaction of 12 with 2 K[B(s-Bu)3H] in THF at −70 °C gave a deep violet solution of L2Bi,17 which reacts with diphenyldichalcogenides PhEEPh to yield monorganobismuth(III) compounds L2Bi(EPh)2 (E = S (13), Se (14), Te (15)), which are stable enough to be isolated in good yields (Scheme 4). The 1H and 13C NMR spectra of 13−15 contained only one set of signals in both aromatic and aliphatic regions, and the signals of CH2N and (CH3)2N groups were observed as sharp singlets in the 1H NMR spectra. These findings indicate a rigid symmetrical pseudomeridional coordination of the ligand L2 as proved later on by their structures in the solid state (see further discussion). Importantly, 13−15 showed no tendency for redistribution as in the case of 9−11. Only 15 showed lower stability in solution and decomposed to a black insoluble material and mixture of products in a period of several days similarly to tellurium-containing compounds 8 and 11. This finding supports our hypothesis that the presence of the second coordinated nitrogen atom is important for the stabilization of monoorganobismuth compounds L2Bi(EPh)2. The molecular structure of 13 was established using X-ray diffraction analysis and is depicted together with corresponding structural parameters in Figure 7. The central bismuth atom

Figure 7. ORTEP plot of a molecule of 13. Hydrogen atoms are omitted for clarity. Selected bond lengths (Å) and angles (deg): Bi(1)−C(1) 2.204(4), Bi(1)−N(1) 2.550(3), Bi(1)−N(2) 2.581(4), Bi(1)−S(1) 2.7279(11), Bi(1)−S(2) 2.7909(11), N(1)−Bi(1)−N(2) 145.07(12), S(1)−Bi(1)−S(2) 170.74(3). 244

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61.3; H, 5.6. 1H NMR (400 MHz, C6D6): δ 1.12 (d, 12H, CH(CH3)2), 3.24 (sept, 2H, CH(CH3)2), 6.91 (m, 6H, SPh-H3,4,5), 7.09 (m, 2H, L-Ar-H), 7.19 (m, 4H, L-Ar-H), 7.53 (d, 4H, SPh-H2,6), 8.07 (s, 1H, CHN), 8.83 (d, 1H, L-Ar-H). 13C NMR (100.61 MHz, C6D6): δ 25.1 (s, CH(CH3)2), 29.1 (s, CH(CH3)2), 124.4, 126.7, 126.9, 129.2, 130.3, 133.4, 133.5, 135.6, 136.5, 138.5, 139.4, 140.2, 145.7, 145.9 (s, L-Ar-C and SPh-C), 166.5 (s, CHN). Synthesis of [o-C6H4(CHNC6H3(i-Pr)2-2,6)]Sb(SePh)2 (3). Compound 3 was prepared analogously to the procedure described for 2. PhSeSePh (0.34 g, 1.1 mmol) with 1 (0.42 g, 0.27 mmol) in toluene (30 mL) gave after workup yellow crystals of 3. Yield: 0.34 g (45%), mp 129 °C. Anal. Calcd for C31H32NSe2Sb (MW 698.28): C, 53.3; H, 4.6. Found: C, 53.0; H, 4.7. 1H NMR (400 MHz, C6D6): δ 1.12 (d, 12H, CH(CH3)2), 3.24 (sept, 2H, CH(CH3)2), 6.90 (m, 6H, SePh-H3,4,5), 7.07 (m, 2H, L-Ar-H), 7.21 (m, 4H, L-Ar-H), 7.62 (d, 4H, SePh-H2,6), 8.05 (s, 1H, CHN), 8.79 (d, 1H, L-Ar-H). 13C NMR (100.61 MHz, C6D6): δ 25.1 (s, CH(CH3)2), 29.0 (s, CH(CH3)2), 124.3, 126.6, 127.2, 129.3, 129.9, 130.0, 133.2, 133.5, 137.0, 139.2, 140.0, 140.1, 142.7, 145.8 (s, L-Ar-C and SePh-C), 166.3 (s, CHN). Synthesis of [o-C6H4(CHNC6H3(i-Pr)2-2,6)]Sb(TePh)2 (4). A benzene (5 mL) solution of PhTeTePh (161 mg, 0.39 mmol) was added in one portion to a solution of 1 (152 mg, 0.098 mmol) in benzene (20 mL) and stirred for 1 h at rt. The reaction mixture was evaporated in vacuo. The remaining red solid was washed with hexane (5 mL) to give red powder of 4, which was dried in vacuo. Yield: 190 mg (61%), mp 96 °C (dec), melts at 114 °C to dark red oil. Anal. Calcd for C31H32NSbTe2 (MW 795.56): C, 46.8; H, 4.1. Found: C, 46.9; H, 4.3. 1H NMR (400 MHz, C6D6): δ 1.10 (d, 12H, CH(CH3)2), 3.20 (sept, 2H, CH(CH3)2), 6.77 (m, 4H, TePh-H3,5), 6.90 (m, 2H, TePh-H4), 7.02 (m, 3H, L-Ar-H), 7.12 (m, 3H, L-Ar-H), 7.73 (d, 4H, TePh-H2,6), 8.00 (s, 1H, CHN), 8.74 (d, 1H, L-Ar-H). 13C NMR (100.61 MHz, C6D6): δ 25.2 (s, CH(CH3)2), 29.0 (s, CH(CH3)2), 111.3, 124.3, 126.5, 127.8, 129.6, 129.8, 132.9, 133.9, 134.8, 139.1, 139.9, 141.2, 144.1, 146.2 (s, L-Ar-C and TePh-C), 165.9 (s, CHN). Synthesis of [o-C6H4(CHNC6H3(i-Pr)2-2,6)]BiCl2 (5). A hexane solution of n-BuLi (4.6 mL, 7.41 mmol, 1.6 M solution) was added to a precooled (−70 °C) solution of L1Br (2.55 g, 7.41 mmol) in diethyl ether (30 mL) and stirred for 30 min at −70 °C. The resulting yellow suspension of L1Li was added to a precooled solution (−70 °C) of BiCl3 (2.34 g, 7.41 mmol) in diethyl ether (60 mL). The reaction mixture was allowed to warm to rt and stirred for an additional 12 h. The volume of the reaction mixture was reduced to approximately 20 mL in vacuo, the resulting suspension was filtered, and the insoluble material was washed with hexane (20 mL). The remaining insoluble solid was extracted with dichloromethane (30 mL), and the extract was evaporated and dried in vacuo, giving a yellowish powder, which was characterized as 5. Yield: 2.62 g (65%), mp 210 °C, starts to become gray and gradually decomposes. Anal. Calcd for C19H22BiCl2N (MW 544.28): C, 41.9; H, 4.1. Found: C, 42.2; H, 4.3. 1H NMR (400 MHz, CDCl3): δ 1.21 (d, 6H, CH(CH3)2), 1.34 (d, 6H, CH(CH3)2), 3.20 (sept, 2H, CH(CH3)2), 7.32 (m, 3H, C6H3iPr2-2,6), 7.81 (dd, 1H, LAr-H), 8.06 (dd, 1H, L-Ar-H), 8.35 (d, 1H, L-Ar-H), 9.37 (d, 1H, LAr-H), 9.43 (s, 1H, CHN). 13C NMR (100.61 MHz, CDCl3): δ 24.3 (s, CH(CH3)2), 25.6 (s, CH(CH3)2), 28.8 (s, CH(CH3)2), 124.4, 127.8, 129.5, 136.5, 138.6, 139.8, 141.2, 143.6, 147.0, (s, L-Ar-C), 179.4 (s, CHN), 215.4 (s, L-Ar-C1). Synthesis of [o-C6H4(CHNC6H3(i-Pr)2-2,6)]2Bi(SPh) (6). K[B(s-Bu)3H] as a 1 M THF solution (1.6 mL, 1.6 mmol) was added dropwise to a solution of 5 (429 mg, 0.79 mmol) in THF (15 mL) at −80 °C and stirred for 30 min at this temperature. The reaction mixture turned a deep violet color during addition of K[B(s-Bu)3H], and evolution of hydrogen gas was obvious. A solution of PhSSPh (172 mg, 0.79 mmol) in THF (5 mL) was added to this cooled solution, and the reaction mixture was allowed to reach rt; during warming, the reaction mixture turned a yellow color. The resulting solution was stirred for an additional 24 h and then evaporated in vacuo. The remaining solid was extracted with toluene (20 mL), and the yellow extract was evaporated. Addition of hexane (10 mL) and storage at 5 °C for several hours gave yellow crystals of 6, which were

Bi(1) is strongly coordinated by the NCN donor set of the pincer ligand L2, as demonstrated by the bond lengths Bi(1)− N(1) 2.550(3) and Bi(1)−N(2) 2.581(4) Å (∑vdW(Bi, N) = 3.55 Å, ∑cov(Bi, N) = 2.22 Å).14 The coordination polyhedron around the central atom is best described as a distorted square pyramid with the ipso-carbon atom located in the apical position. Both nitrogen atoms and sulfur atoms are coordinated mutually in trans positions in the basal plane, as shown by the bonding angles N(1)−Bi(1)−N(2) and S(1)−Bi(1)−S(2) of 145.07(12)° and 170.74(3)°, respectively, and the lone pair is located in trans position to the ipso-carbon atom. The bond lengths Bi(1)−S(1) 2.7279(11) and Bi(1)−S(2) 2.7909(11) Å indicate the presence of covalent bonds (∑cov(Bi, S) = 2.54 Å),14 but these bonds are significantly elongated in comparison with the CN-chelated analogue 9 (the range found in 9 is 2.5591(18)−2.6430(17) Å). Importantly, there is no close intermolecular contact of the central bismuth atom and other sulfur atoms in the structure of 13. This fact contrasts with the CN-chelated monoorganobismuth compounds 9−11. Unfortunately, all attempts to grow single crystals of 14 or 15 suitable for X-ray diffraction analyses failed.



CONCLUSION It was demonstrated, that both CN-chelated antimony(I) and in situ prepared CN- or NCN-chelated bismuth(I) compounds are good starting compounds for the preparation of a variety of phenylchalcogenolates including highly reactive and unstable tellurolates. Tellurolates were shown to decompose after a prolonged period in solution either to the starting antimony(I) compound 1 and diphenylditelluride or to a mixture of decomposition products in the case of bismuth tellurolates 8, 11, and 15. It was also demonstrated that the CN-chelated monoorganobismuth compounds L1Bi(EPh)2 are unstable in solution and convert to the corresponding diroganobismuth derivatives L12Bi(EPh) (E = S, Se, Te) and Bi(EPh)3. Such behavior of bismuth compounds is suppressed using the potentially terdentate pincer-type ligand L2, which saturates the central bismuth atom by two N→Bi interactions, and compounds L2Bi(EPh)2 show no tendency for a similar redistribution.



EXPERIMENTAL SECTION

All air- and moisture-sensitive manipulations were carried out under an argon atmosphere using standard Schlenk tube techniques. All solvents were dried by standard procedures and distilled prior to use. 1H and 13 C NMR spectra were recorded on a Bruker 400 MHz spectrometer, using a 5 mm tunable broad-band probe. Appropriate chemical shifts in 1H and 13C NMR spectra were related to the residual signals of the solvent (CDCl3: δ(1H) = 7.27 ppm and δ(13C) = 77.23 ppm; C6D6: δ(1H) = 7.16 ppm, δ(13C) = 128.39 ppm). The starting compounds, SbCl3 (99.999%), BiCl3 (99.999%), PhSSPh (99%), PhSeSePh (98%), and PhTeTePh (98%), were obtained from commercial suppliers and used as delivered. The ligand L1Br21 and compounds L14Sb4 (1)13 and L2BiCl222 (12) were prepared according to published procedures. Elemental analyses were performed on a LECO-CHNS-932 analyzer. Synthesis of [o-C6H4(CHNC6H3(i-Pr)2-2,6)]Sb(SPh)2 (2). A toluene (5 mL) solution of PhSSPh (0.175 g, 0.8 mmol) was added in a period of 5 min to a solution of 1 (0.31 g, 0.2 mmol) in toluene (30 mL) and stirred for 1 h at rt. The initially red solution turned yelloworange within this time. The reaction mixture was evaporated to a final volume of approximately 3 mL, and hexane (10 mL) was added. The resulting solution was left for crystallization at −30 °C for several days to give yellow crystals of 2, which were filtered off at low temperature (−30 °C) and dried in vacuo. Yield: 0.27 g (55%), mp 165 °C. Anal. Calcd for C31H32NS2Sb (MW 604.49): C, 61.6; H, 5.3. Found: C, 245

dx.doi.org/10.1021/om3010383 | Organometallics 2013, 32, 239−248

Organometallics

Article

filtered off, washed with hexane, and dried in vacuo. Yield: 230 mg (69%), mp 200−202 °C. Anal. Calcd for C44H49N2BiS (MW 846.94): C, 62.4; H, 5.8. Found: C, 62.5; H, 5.6. 1H NMR (400 MHz, C6D6): δ 0.93 (d, 24H, CH(CH3)2), 2.89 (sept-broadened, 4H, CH(CH3)2), 6.76 (t, 1H, SPh-H4), 6.86 (dd, 2H, SPh-H3,5), 7.06 (m, 10H, L-ArH), 7.34 (dd, 2H, L-Ar-H), 7.63 (d, 2H, SPh-H2,6), 8.23 (s, 2H, CHN), 9.14 (strongly broadened, 2H, L-Ar-H). 13C NMR (100.61 MHz, C6D6): δ 24.8 (s, CH(CH3)2), 28.7 (s, CH(CH3)2), 123.8, 124.8, 125.8, 128.6, 128.7, 129.0, 129.6, 134.4, 135.6, 135.8, 139.4, 141.5, 142.6, 148.7 (s, L-Ar-C and SPh-C), 170.0 (s, CHN). Synthesis of [o-C6H4(CHNC6H3(iPr)2-2,6)]2Bi(SePh) (7). Compound 7 was prepared analogously to the procedure described for 6. K[B(s-Bu)3H] as a 1 M THF solution (1.7 mL, 1.7 mmol) with 5 (460 mg, 0.85 mmol) in THF (15 mL) at −80 °C followed by addition of PhSeSePh (263 mg, 0.85 mmol) in THF (5 mL) gave after workup yellow-orange crystals of 7. Yield: 270 mg (72%), mp 202− 205 °C. Anal. Calcd for C44H49N2BiSe (MW 893.83): C, 59.1; H, 5.5. Found: C, 59.0; H, 5.8. 1H NMR (400 MHz, C6D6): δ 0.95 (d, 24H, CH(CH3)2), 2.91 (sept-broadened, 4H, CH(CH3)2), 6.79 (m, 3H, SePh-H3,4,5), 7.07 (m, 10H, L-Ar-H), 7.34 (dd, 2H, L-Ar-H), 7.73 (d, 2H, SePh-H2,6), 8.20 (s, 2H, CHN), 9.18 (strongly broadened, 2H, L-Ar-H). 13C NMR (100.61 MHz, C6D6): δ 24.8 (s, CH(CH3)2), 28.8 (s, CH(CH3)2), 123.9, 125.7, 125.8, 128.5, 128.7, 129.1, 132.1, 135.7, 135.9, 136.5, 139.4, 142.5, 144.0, 148.8 (s, L-Ar-C and SePh-C), 170.0 (s, CHN). Synthesis of [o-C6H4(CHNC6H3(i-Pr)2-2,6)]2Bi(TePh) (8). Compound 8 was prepared analogously to the procedure described for 6. K[B(s-Bu)3H] as a 1 M THF solution (1.5 mL, 1.5 mmol) with 5 (410 mg, 0.75 mmol) in THF (15 mL) at −80 °C followed by addition of PhTeTePh (309 mg, 1.5 mmol) in THF (5 mL) gave after workup yellow-orange crystals of 7. Yield: 200 mg (56%), mp 146 °C (dec). Anal. Calcd for C44H49N2BiTe (MW 942.47): C, 56.1; H, 5.2. Found: C, 56.5; H, 5.4. 1H NMR (400 MHz, C6D6): δ 0.93 (d, 24H, CH(CH3)2), 2.92 (sept-broadened, 4H, CH(CH3)2), 6.69 (m, 2H, TePh-H3,5), 6.82 (m, 1H, TePh-H4), 7.08 (m, 10H, L-Ar-H), 7.30 (dd, 2H, L-Ar-H), 7.84 (d, 2H, TePh-H2,6), 8.14 (s, 2H, CHN), 9.17 (strongly broadened, 2H, L-Ar-H). 13C NMR spectra could not be observed due to the low stability in solution, and during attempts to acquire a reasonable spectrum the solution starts to be contaminated by decomposition products, which makes the convincing assignment impossible. Synthesis of [o-C6H4(CHNC6H3(iPr)2-2,6)]Bi(SPh)2 (9). K[B(s-Bu)3H] as a 1 M THF solution (1.3 mL, 1.3 mmol) was added dropwise to a solution of 5 (350 mg, 0.64 mmol) in THF (15 mL) at −80 °C and stirred for 30 min at this temperature. The reaction mixture turned a deep violet color during addition of K[B(s-Bu)3H], and evolution of hydrogen gas was obvious. A solution of PhSSPh (140 mg, 0.64 mmol) in THF (5 mL) was added to this cooled solution, and the reaction mixture was allowed to reach rt; during warming, the reaction mixture turned a yellow color. The resulting solution was stirred for an additional 10 min and then evaporated in vacuo. The remaining solid was extracted with hexane (30 mL), the yellow extract was slightly concentrated, and storage of this solution for several days at 5 °C gave yellow-orange single crystals of 9, which were filtered off, washed with hexane, and dried in vacuo. Yield: 66 mg (15%), mp 173 °C. Anal. Calcd for C31H32N2BiS2 (MW 691.72): C, 53.8; H, 4.7. Found: C, 53.6; H, 4.9. 1H NMR (400 MHz, C6D6): δ 1.08 (d, 12H, CH(CH3)2), 3.09 (sept, 2H, CH(CH3)2), 6.79 (m, 2H, SPh-H4), 6.93 (m, 4H, SPh-H3,5), 7.10 (m, 4H, L-Ar-H), 7.30 (m, 2H, L-Ar-H), 7.43 (d, 4H, SPh-H2,6), 8.21 (s, 1H, CHN), 9.38 (d, 1H, L-Ar-H). 13C NMR (100.61 MHz, C6D6): δ 24.9 (s, CH(CH3)2), 29.0 (s, CH(CH3)2), 124.2, 126.5, 127.0, 128.7, 128.8, 135.9, 136.3, 137.1, 136.5, 139.7, 142.5, 142.8, 146.9, (s, L-Ar-C and SPh-C), 171.5 (s, CHN), (L-Ar-C1) not detected. Synthesis of [o-C6H4(CHNC6H3(iPr)2-2,6)]Bi(TePh)2 (11). K[B(s-Bu)3H] as a 1 M THF solution (1.5 mL, 1.5 mmol) was added dropwise to a solution of 5 (405 mg, 0.74 mmol) in THF (15 mL) at −80 °C and stirred for 30 min at this temperature. The reaction mixture turned a deep red color during addition of K[B(sBu)3H], and evolution of hydrogen gas was obvious. A solution of

PhTeTePh (304 mg, 0.74 mmol) in THF (5 mL) was added to this cooled red solution, and the reaction mixture was allowed to reach rt. The resulting solution was stirred for an additional 10 min and then evaporated in vacuo. The remaining solid was washed with hexane (15 mL), and in this fraction compound 8 was detected. The remaining solid was extracted with toluene (20 mL) to give a deep violet solution, which was concentrated to approximately 5 mL, and storage of this solution at −30 °C for several days afforded deep violet crystals of 11, which were filtered off, washed with hexane, and dried in vacuo. Yield: 66 mg (10%), mp 127 °C (dec), melts at 154 °C to a black oil. Anal. Calcd for C31H32N2BiTe2 (MW 882.79): C, 42.2; H, 3.7. Found: C, 42.6; H, 3.9. 1H NMR (400 MHz, C6D6): δ 1.07 (d, 12H, CH(CH3)2), 3.05 (sept, 2H, CH(CH3)2), 6.84 (m, 6H, 4H, TePhH3,4,5), 7.06 (m, 5H, L-Ar-H), 7.21 (m, 2H, L-Ar-H), 7.74 (d, 4H, TePh-H2,6), 8.03 (s, 1H, CHN), 9.60 (d, 1H, L-Ar-H). 13C NMR (100.61 MHz, C6D6): δ 24.9 (s, CH(CH3)2), 29.1 (s, CH(CH3)2), 108.0, 124.3, 126.3, 127.0, 128.0, 129.3, 135.9, 137.3, 139.4, 142.2, 142.3, 147.0, 150.4, (s, L-Ar-C and SPh-C), 169.9 (s, CHN), (L-ArC1) not detected. Synthesis of [o,o-C6H3(CH2NMe2)2]Bi(SPh)2 (13). K[B(s-Bu)3H] as a 1 M THF solution (1.9 mL, 1.9 mmol) was added dropwise to a solution of 12 (439 mg, 0.93 mmol) in THF (15 mL) at −80 °C and stirred for 30 min at this temperature. The reaction mixture turned a deep violet color during addition of K[B(s-Bu)3H], and evolution of hydrogen gas was obvious. A solution of PhSSPh (204 mg, 0.93 mmol) in THF (5 mL) was added to this cooled violet solution, and the reaction mixture was allowed to reach rt; during warming, the reaction mixture turned a yellow-brown color. The resulting solution was stirred for an additional 4 h and then evaporated in vacuo. The remaining solid was extracted with toluene (20 mL), the yellow-orange extract was evaporated to a final volume of approximately 3 mL, and hexane (10 mL) was added. Storage of this mixture at −30 °C for several hours gave a yellow-orange oily material, which was separated by decantation. Hexane (10 mL) was added to this oil, and the mixture was stirred for 5 h, resulting in precipitation of a yellow powder, which was filtered, dried in vacuo, and characterized as 13. Yield: 330 mg (57%), mp 112 °C (dec), melts at 145 °C to red oil. Anal. Calcd for C24H29N2BiS2 (MW 618.62): C, 46.6; H, 4.7. Found: C, 46.9; H, 4.9. 1 H NMR (400 MHz, C6D6): δ 2.40 (s, 12H, N(CH3)2), 3.91 (s, 4H, NCH2), 6.94 (dd, 2H, SPh-H4), 7.14 (dd, 4H, SPh-H3,5), 7.22 (m, 3H, L-Ar-H), 7.49 (d, 4H, SPh-H2,6). 13C NMR (100.61 MHz, C6D6): δ 48.0 (s, N(CH3)2), 69.3 (s, NCH2), 124.1, 128.7, 129.0, 129.1, 134.7, 144.4, 152.2 (s, L-Ar-C and SPh-C), 197.7 (s, L-Ar-C1). Synthesis of [o,o-C6H3(CH2NMe2)2]Bi(SePh)2 (14). Compound 14 was prepared analogously to the procedure described for 13. K[B(sBu)3H] as a 1 M THF solution (1.6 mL, 1.6 mmol) with 12 (382 mg, 0.81 mmol) in THF (15 mL) at −80 °C followed by addition of PhSeSePh (253 mg, 0.81 mmol) in THF (5 mL) gave after workup orange crystals of 14. Yield: 360 mg (62%), mp 124−127 °C. Anal. Calcd for C24H29N2BiSe2 (MW 712.41): C, 40.5; H, 4.1. Found: C, 40.6; H, 4.4. 1H NMR (400 MHz, C6D6): δ 2.44 (s, 12H, N(CH3)2), 3.88 (s, 4H, NCH2), 6.99 (dd, 2H, SePh-H4), 7.09 (dd, 4H, SePhH3,5), 7.20 (m, 3H, L-Ar-H), 7.64 (d, 4H, SePh-H2,6). 13C NMR (100.61 MHz, C6D6): δ 48.1 (s, N(CH3)2), 69.7 (s, NCH2), 124.5, 128.2, 128.5, 128.6, 136.5, 151.8 (s, L-Ar-C and SePh-C), (L-Ar-C1) and (SePh-C1) not detected. Synthesis of [o,o-C6H3(CH2NMe2)2]Bi(TePh)2 (15). Compound 15 was prepared analogously to the procedure described for 13. K[B(sBu)3H] as a 1 M THF solution (1.9 mL, 1.9 mmol) with 12 (447 mg, 0.95 mmol) in THF (15 mL) at −80 °C followed by addition of PhTeTePh (389 mg, 0.95 mmol) in THF (5 mL) gave after workup deep violet crystals of 15. Yield: 255 mg (33%), mp 96 °C(dec). Anal. Calcd for C24H29N2BiTe2 (MW 809.69): C, 35.6; H, 3.6. Found: C, 35.9; H, 3.4. 1H NMR (400 MHz, C6D6): δ 2.42 (s, 12H, N(CH3)2), 3.75 (s, 4H, NCH2), 6.95 (dd, 4H, TePh-H3,5), 7.00 (dd, 4H, TePhH4), 7.17 (m, 3H, L-Ar-H), 7.85 (d, 4H, TePh-H2,6). 13C NMR (100.61 MHz, C6D6): δ 49.7 (s, N(CH3)2), 72.2 (s, NCH2), 110.0 (TePh-C1), 126.4, 128.9, 129.3, 129.6, 142.0, 151.6 (s, L-Ar-C and TePh-C), (L-Ar-C1) not detected. 246

dx.doi.org/10.1021/om3010383 | Organometallics 2013, 32, 239−248

Organometallics

Article

X-ray Crystallography. Suitable single crystals of all studied compounds were mounted on a glass fiber with oil and measured on a KappaCCD four-circle diffractometer with a CCD area detector by monochromatized Mo Kα radiation (λ = 0.71073 Å) at 150(1) K (except of 2, which was measured at 291 K, because the single crystals are mechanically unstable at temperatures lower than 283 K, and thus the obtained data set and resulting thermal motions of atoms are not ideal). The numerical23 absorption corrections from crystal shape were applied for all crystals. The structures were solved by the direct method (SIR92)24 and refined by a full matrix least-squares procedure based on F2 (SHELXL97).25 Hydrogen atoms were fixed in idealized positions (riding model) and assigned temperature factors Hiso(H) = 1.2Ueq (pivot atom) or 1.5Ueq for the methyl moiety with C−H = 0.96, 0.97, and 0.93 Å for methyl, methylene, and hydrogen atoms in the aromatic ring, respectively. The final difference maps displayed no peaks of chemical significance, as the highest peaks and holes are in close vicinity (∼1 Ǻ ) of heavy atoms. Although one of the carbon atoms in the methyl groups of 6 and 7 does not have an ideal shape, the different treatment of these atoms, for example, ISOR SHELXL instruction, or splitting into two positions gave no better results. On the other hand, in 8, the methyl groups were constructed in two positions, as well as in the structure of 5, where two overlapping dichloromethane solvent molecules were split. There is disordered solvent (toluene) in the structure of 11. Attempts were made to model this disorder or split it into two positions, but these were unsuccessful. PLATON/SQUEZZE26 software was used to correct the data for the presence of disordered solvent. A potential solvent volume of 814 Ǻ 3 was found; 218 electrons per unit cell worth of scattering were located in the void. The calculated stoichiometry of solvent was calculated to be four molecules of toluene per unit cell, which results in 200 electrons per unit cell. The molecular structure of 5 has been treated with SuperFlip software.27 Crystallographic data for structural analysis have been deposited with the Cambridge Crystallographic Data Centre, CCDC nos. 905878−905887. Copies of this information may be obtained free of charge from The Director, CCDC, 12 Union Road, Cambridge CB2 1EY, UK (fax: +44-1223-336033; e-mail: deposit@ ccdc.cam.ac.uk or www: http://www.ccdc.cam.ac.uk).



Ziller, J. W.; Mincher, B. J.; Evans, J. W. Inorg. Chem. 2011, 50, 1513. (f) Casely, I. J.; Ziller, J. W.; Fang, M.; Furche, F.; Evans, J. W. J. Am. Chem. Soc. 2011, 133, 5244. (g) Dostál, L.; Jambor, R.; Růzǐ čka, A.; Holeček, J. Organometallics 2008, 27, 2169. (h) Balázs, L.; Breunig, H. J.; Lork, E.; Silvestru, C. Eur. J. Inorg. Chem. 2003, 1361. (i) Opris, L. M.; Silvestru, A.; Silvestru, C.; Breunig, H. J.; Lork, E. Dalton Trans. 2004, 3575. (2) Šimon, P.; De Proft, F.; Jambor, R.; Růzǐ čka, A.; Dostál, L. Angew. Chem., Int. Ed. 2010, 49, 5468. (3) Jambor, R.; Kašná, B.; Kirschner, K. N.; Schürmann, M.; Jurkschat, K. Angew. Chem., Int. Ed. 2008, 47, 1650. (4) For representative examples see: (a) Power, P. P. Chem. Rev. 1999, 99, 3463. (b) Fischer, R. C.; Power, P. P. Chem. Rev. 2010, 110, 3877. (c) Power, P. P. Nature 2010, 463, 171. , and references therein. (d) Wang, Y.; Robinson, G. H. Inorg. Chem. 2011, 50, 12326. (e) Sen, S. S.; Khan, S.; Samuel, P. P.; Roesky, H. W. Chem. Sci. 2012, 3, 659. (f) Asay, M.; Jones, C.; Driess, M. Chem. Rev. 2011, 221, 354. (g) Mizuhata, Y.; Sasamori, T.; Tokitoh, N. Chem. Rev. 2009, 109, 3479. (5) Summerscales, O. T.; Wang, X.; Power, P. P. Angew. Chem., Int. Ed. 2010, 49, 4788. (6) Green, S. P.; Jones, C.; Stasch, A. Science 2007, 318, 1754. (7) For example see: (a) Bonyhady, S. J.; Green, S. P.; Jones, C.; Nembenna, S.; Stasch, A. Angew. Chem., Int. Ed. 2009, 48, 2973. (b) Choong, S. L.; Schenk, C.; Stasch, A.; Dange, D.; Jones, C. Chem. Commun. 2012, 48, 2504. (c) Jones, C.; Bonyhady, S. J.; Holzmann, N.; Frenking, G.; Stasch, A. Inorg. Chem. 2011, 50, 12315. (d) Li, J.; Schenk, C.; Goedecke, C.; Frenking, G.; Jones, C. J. Am. Chem. Soc. 2011, 133, 18622. (e) Stasch, A.; Jones, C. Dalton Trans. 2011, 40, 5659. (f) Rekken, B. D.; Brown, T. M.; Fettinger, J. C.; Tuononen, H. M.; Power, P. P. J. Am. Chem. Soc. 2012, 134, 6504. (8) (a) Dostál, L.; Jambor, R.; Růzǐ čka, A.; Lyčka, A.; Brus, J.; De Proft, F. Organometallics 2008, 27, 6059. (b) Bouška, M.; Dostál, L.; Růzǐ čka, A.; Beneš, L.; Jambor, R. Chem.Eur. J. 2011, 17, 450. (c) Bouška, M.; Dostál, L.; De Proft, F.; Růzǐ čka, A.; Lyčka, A.; Jambor, R. Chem.Eur. J. 2011, 17, 455. (d) Bouška, M.; Dostál, L.; Padělková, Z.; Herres-Pawlis, S.; Jurkschat, K.; Lyčka, A.; Jambor, R. Angew. Chem., Int. Ed. 2012, 51, 3478. (e) Šimon, P.; Jambor, R.; Růzǐ čka, A.; Lyčka, A.; De Proft, F.; Dostál, L. Dalton Trans. 2012, 41, 5140. (9) (a) Shimada, S.; Yamazaki, O.; Tanaka, T.; Suzuki, Y.; Tanaka, M. J. Organomet. Chem. 2004, 689, 3012. (b) Anderson, K. M.; Baylies, C. J.; Jahan, A. H. M. M.; Norman, N. C.; Orpen, A. G.; Starbuck, J. Dalton Trans. 2003, 3270. (c) Briand, G. G.; Decken, A.; Hunter, N. M.; Lee, G. M.; Melanson, J. A.; Owen, E. M. Polyhderon 2012, 31, 796. (d) Preut, H.; Praeckel, H.; Huber, F. Acta Crystallogr. Sect. C: Cryst. Struct. Commun. 1986, 42, 1138. (e) Preut, H.; Huber, F.; Hengstmann, K. H. Acta Crystallogr. Sect. C: Cryst. Struct. Commun. 1988, 44, 486. (f) Wieber, M.; Hohl, H.; Burschka, Ch. Z. Anorg. Allg. Chem. 1990, 583, 113. (g) Hengstmann, K. H.; Huber, F.; Preut, H. Acta Crystallogr. Sect. C: Cryst. Struct. Commun. 1991, 47, 2029. (10) Traut, S.; Hahnel, A. P.; von Hanisch, C. Dalton Trans. 2011, 40, 1365. (11) (a) Calderazzo, F.; Morvillo, A.; Pelizzi, G.; Poli, R.; Ungari, F. Inorg. Chem. 1988, 27, 3730. (b) Mugesh, G.; Singh, B. H.; Butcher, R. J. J. Chem. Res. (S) 1999, 416. (12) (a) Breunig, H. J.; Ghesner, I.; Lork, E. J. Organomet. Chem. 2002, 664, 130. (b) Sasamori, T.; Mieda, E.; Takeda, N.; Tokitoh, N. Angew. Chem., Int. Ed. 2005, 44, 3717. (c) Sasamori, T.; Mieda, E.; Tokitoh, N. Bull. Chem. Soc. Jpn. 2007, 80, 2425. (d) Breunig, H. J.; Ebert, K. H.; Schulz, R. E.; Wieber, M.; Sauer, I. Z. Naturforsch., B: Chem. Sci. 1995, 50, 735. (e) Konchenko, S. N.; Pushkarevsky, N. A.; Scheer, M. J. Organomet. Chem. 2002, 658, 204. (f) Breunig, H. J.; Lork, E.; Moldovan, O.; Wagner, R. Z. Anorg. Allg. Chem. 2008, 634, 1397. (13) Dostál, L.; Jambor, R.; Růzǐ čka, A.; Šimon, P. Eur. J. Inorg. Chem. 2011, 2380. (14) (a) Pyykkö, P.; Atsumi, M. Chem.Eur. J. 2009, 15, 186. (b) Pyykkö , P.; Atsumi, M. Chem.Eur. J. 2009, 15, 12770.

ASSOCIATED CONTENT

S Supporting Information *

Table S1 containing all crystallographic data of studied compounds and Figure S1 with the molecular structure of 9, all crystal data and structure refinement, atomic coordinates, anisotropic displacement parameters, and geometric data for studied compounds are available free of charge via the Internet at http://pubs.acs.org.



AUTHOR INFORMATION

Corresponding Author

*Fax: +420466037068. Tel: +420466037163. E-mail: libor. [email protected]. Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS The authors would like to thank the Grant Agency of the Czech Republic (P207/10/0130). REFERENCES

(1) For examples see: (a) Khan, S.; Samuel, P. P.; Michel, R.; Dieterich, J. M.; Mata, R. A.; Demers, J.-P.; Lange, A.; Roesky, H. W.; Stalke, D. Chem. Commun. 2012, 48, 4890. (b) Khan, S.; Michel, R.; Dieterich, J. M.; Mata, R. A.; Roesky, H. W.; Demers, J.-P.; Lange, A.; Stalke, D. J. Am. Chem. Soc. 2011, 133, 17889. (c) Mairychová, B.; Dostál, L.; Růzǐ čka, A.; Fulem, M.; Růzǐ čka, K.; Lyčka, A.; Jambor, R. Organometallics 2011, 30, 5904. (d) Balazs, L.; Breunig, H. J.; Lork, E.; Soran, A.; Silvestru, C. Inorg. Chem. 2006, 45, 2341. (e) Casely, I. J.; 247

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(c) Pyykkö, P.; Riedel, S.; Patzschke, M. Chem.Eur. J. 2005, 11, 3511. (15) Kuzmina, L. G.; Bokii, N. G.; Timofeeva, T. V.; Struchkov, Y. T.; Kravtsov, D. N.; Pombrik, S. I. J. Struct. Chem. 1978, 19, 328. (16) (a) Breunig, H. J.; Koenigsmann, L.; Lork, E.; Nema, M.; Philipp, N.; Silvestru, C.; Soran, A.; Varga, R. A.; Wagner, R. Dalton Trans. 2008, 1831. (b) Breunig, H. J.; Nema, M.; Silvestru, C.; Soran, A.; Varga, R. A. Z. Anorg. Allg. Chem. 2010, 636, 2378. (17) The formulation LBi is only informative as both in situ reduced bismuth compounds have most probably oligomeric structures in solution. Unfortunately, we have no experimental data to be able to speculate about their exact structures. (18) (a) Urbanová, I. Thesis, University of Pardubice, 2012. (b) Opris, L. M.; Silvestru, A.; Silvestru, C.; Breunig, H. J.; Lork, E. Dalton Trans. 2003, 4367. (19) Sommer, H.; Eichhöfer, A.; Fenske, D. Z. Anorg. Allg. Chem. 2008, 634, 436. (20) Similar studies dealing with compound 11 were hampered by its low stability in solution. (21) Zhao, D.; Gao, W.; Mu, Y.; Ye, L. Chem.Eur. J. 2010, 16, 4394. (22) Atwood, D. A.; Cowley, A. H.; Ruiz, J. Inorg. Chim. Acta 1992, 198−200, 271. (23) Coppens, P. In Crystallographic Computing; Ahmed, F. R.; Hall, S. R.; Huber, C. P.; Eds.; Munksgaard: Copenhagen 1970; p 255. (24) Altomare, A.; Cascarone, G.; Giacovazzo, C.; Guagliardi, A.; Burla, M. C.; Polidori, G.; Camalli, M. J. Appl. Crystallogr. 1994, 27, 1045. (25) Sheldrick, G. M. SHELXL-97, A Program for Crystal Structure Refinement; University of Göttingen: Germany, 1997. (26) Spek, A. L. Acta Crystalllogr., Sect. A 1990, 46, C34. (27) Palatinus, L.; Chapuis, G. J. Appl. Crystallogr. 2007, 40, 786.

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