Organometallics 1996, 14, 355-364
355
Cyclometalated Platinum(I1) Compounds with Fluorinated Iminic Ligands: Synthesis and Reactivity Tuning. Crystal Structures of the Compounds [P~M~(RCH=NCH~C~HE)(PP~~)] (R = 2,3,4-C~HF3 and %3-CeH2Fd Margarita Crespo" Departament de Quimica Inorghnica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona, Spain
Xavier Solans and Mer& Font-Bardia Departament de Cristal.lografia, Mineralogia i Dipbsits Minerals, Universitat de Barcelona, Marti i Franqub s l n , 08028 Barcelona, Spain Received June 13, 1994@
[PtzMe4@-SMez)z](1) reacts with fluorinated imines ArCH=NCHzCsH5 (2; Ar = 2,3,4CsHzF3, 2,4,5-C&F3, 2,3-CsH3Fz) to yield the C,N-cyclometalated platinum(I1) compounds [PtMe(RCH=NCHzC6H5)(SMe2)] (3)by ortho metalation with loss of methane. Complexes 3 react with triphenylphosphine to give cyclometalated compounds [PtMe(RCH=NCH2CsH&PPh3)] (4). For R = 2,4,5-Csm3, an excess of PPh, produces metallacycle cleavage, and [PtMe(RCH=NCHzCsH5)(PPh3)zI(5)is formed with the imine acting as a [C-I unidentate ligand. Similarly, reactions of the previously reported compounds [PtMe{RCH=NCH2(22-CsH3F, 5-CsH3F) with PPh3 produce the cyclometalated C~H~C~)}(SM (R~= Z )3,5-C&Fz, I compounds 4. When a n excess of PPh3 is used, compounds 5 are obtained only if there is a fluorine atom adjacent to platinum (F5). 3-5 were characterized by elemental analyses and NMR spectroscopy, and [PtMe(2,3,4-CsHF3CH=NCH2CsH5)(PPh3)1 (4a) and [PtMe(2,3C ~ H Z F ~ C H = N C H Z C ~ H ~ )(4c) ( P Pwere ~ ~ ) characterized ] crystallographically. 4a crystallizes in the monoclinic space group P21/c, with a = 12.475(3) b = 21.642(5) 8,c = 10.497(2) j3 = 96.92(2)", and 2 = 4. 4c crystallizes in the triclinic space group Pi,with a = 12.031(2) b = 13.757(2) A, c = 9.768(2) a = 72.91(2)", j3 = 114.91(1)', y = 104.20(2)", and 2 = 2. Structural and NMR parameters for compounds 4 are discussed in relation to the observed reactivity of these compounds.
A,
A,
A,
A,
Introduction Cyclometalated compounds have been extensively studied because of their potential utility in organic synthesis, and a number of synthetic approaches have been investigated.l Although organopalladium cyclometalated compounds have been the most studied, there are several classical examples of platinum complexes with ortho-metalated nitrogen donor ligands.2 Recent reports of platinum(I1) cyclometalated compounds concern their photochemical and electrochemical propertie^.^,^ Moreover, there is an increasing interest in platinum(I1) and even platinum(rV1 compounds with either bidentate (C,NI5or terdentate (N,C,N' or C,N,N'Y ligands. [F%zMe4@-SMez)zI has been shown to be a good substrate for the synthesis of cyclometalated platinum Abstract published in Advance ACS Abstracts, November 1,1994. (1)(a)Omae, I. Coord. Chem. Reu. 1988,83,137. (b) Omae, I. Chem. Rev. 1979, 79, 287. (2)(a) Cope, A. C.; Siekman, R. W. J. Am. Chem. SOC.1966, 87, 3272. (b) Elder, R. C.; Cruea, R. D.; Morrison, R. F. h o r g . Chem. 1976, 5. 1623. (c) Coue, A. C.: Friedrich, E. C. J.Am. Chem. SOC.1968,90, @
90s. (3) (a) Maestri, M.; Sandrini, D.; von Zelewsky, A.; DeuschelCornioley, C. Inorg. Chem. 1991,30,2476. (b) Minghetti, G.; Pilo, M.; Sanna, G.; Seeberg, R.; Stoccoro, S.; Laschi, F. J. Organomet. Chem. 1993,452,257. (c) Maestri, M.; Deuschel-Comioley, C.; von Zelewsky, A. Coord. Chem. Rev. 1991,111, 117.
(4)von Zelewsky, A.; Suckling, A. P.; Stoeckli-Evans, H. Inorg. Chem. 1993, 32, 4585.
0276-7333195123 14-0355$09.OOIO
compounds containing bidentate (C,N) or terdentate (C,N,N)ligands. For instance, platinum(I1) compounds of the types [PtMe(C,N,N)I7and [PtMe(C,N)(SMez)I8 have been obtained under mild conditions by intramolecular C -H bond activation, followed by reductive elimination of the methane. Analogous reactions for C-X bonds (X = Br, C1, F) have given platinumW) cyclometalated compounds such as [P~M~ZX(C,N,N')I~~~ or [PtMeZX(C,N)(SMez)I In this paper we report the synthesis and reactivity of new cyclometalated platinum(I1) compounds containing fluorinated iminic ligands of the type CsF,H5-,(5)(a) Chattopadhyay, S.; Sinha, C.; Basu, P.; Chakravorty, A. Organometallics 1991, 10, 1135. (b) Newkome, G. R.; Theriot, K. J.; Fronczek, F. R.; Villar, B. Organometallics 1989, 8, 2523. (6) (a) Canty, A. J.; Honeyman, R. T. J. Organomet. Chem. 1990, 387,247. (b) Canty, A. J.;Honeyman, R. T.; Skelton, B. W.; White, A. H. J. Organomet. Chem. 1990,389,277. (c) Constable, E. C.; Henney, R. P.G.; Leese, T. A.; Tocher, D. A. J. Chem. Soc., Chem. Commun. 1990, 513. (d) Wehman-Ooyevaar, I. C. M.; Kapteijn, G. M.; Grove, D. M.; Smeets, W. J. J.;Spek, A. L.; van Koten, G. J.Chem. Soc.,Dalton Trans. 1994, 703. (7) Anderson, C. M.; Crespo, M.; Jennings, M. C.; Lough, A. J.; Ferguson, G.; Puddephatt, R. J. Organometallics 1991,10, 2672. (8) Crespo, M.; Martinez, M.; Sales, J.; Solans, X.; Font-Bardia, M. Organometallics 1992, 11, 1288. (S)Anderson, C. M.; Crespo, M.; Ferguson, G.; Lough, A. J.; Puddephatt, R. J. Organometallics 1992, 11, 1177. (10)(a) Crespo, M.; Martinez, M.; Sales, J. J. Chem. Soc., Chem. Commun. 1992, 822. (b) Crespo, M.; Martinez, M.; Sales, J. Organometallics 1993, 12, 4297.
0 1995 American Chemical Society
356 Organometallics, Vol. 14, No. 1, 1995
Crespo et al.
Scheme 1
activation of the C-H bond followed by elimination of methane to produce compounds 3. The reactions were 0.5 [PtMez(p-SMez)]z + AI-CH=N-CH~-C~HS monitored by lH NMR, and in all cases only one compound was formed. C-F bond activation was not 1 observed, even when an electron-withdrawing fluorine substituent was present in a position adjacent to the ortho-fluorine, as in ligands 2a,c. Thus, when both C-F and C-H are present in the L C H . ortho positions of the aromatic ring, exclusive activation of the latter takes place. This finding may be related t to the higher energy of the C-F bond compared to the 7 2 C-H bond.12 C-F bond activation has been reportedlo t o occur in the presence of weaker C-X (X = H, C1, Br) bonds for systems where activation of C-X bonds would produce a metallacycle that does not contain the C=N group, such as ligands 2h-j (Chart 1). However, in the present system, both C-H and C-F bond activations would lead to five-membered metallacycles containing the iminic functionality. The results reported in this paper, together with others previously obtained, are summarized in Chart 1 CH=NCH2CsH5. We have recently studiedlo the reacand show that C-F bond activation is produced only if tion of several fluorinated iminic ligands with [PtzMerthe aryl ring contains at least three fluorine atoms, with @-SMe2)2](1);C-F bond activation has been achieved two of them in ortho positions (2h-1); when these not only for pentafluorophenyl derivatives but also for requirements are not fulfilled, either no reaction occurs trifluorinated ligands containing fluorine substituents (2m) or C-H bond activation takes place (2a-f). in the two ortho positions such as 2,4,6- and 2,3,6Compounds 3 were characterized by elemental analyC&$'&H=NCH2CsH5. However, no reaction has been sis and lH, 13C,and 19FNMR spectra. In the lH NMR, observed for the ligand 2,6-CsH3F2CHENCH2CsH5. the resonance of the methyl group bound to platinum Thus, the presence of a t least three fluorine atoms appears as a pseudotriplet due to the coupling with lg5seems necessary to produce C-F bond activation. In Pt and coupling constant values (2J(HPt)= ca. 80 Hz) order t o ascertain whether the presence of two fluorines are characteristic for platinum(I1) compounds with in ortho positions is also a requirement for C-F bond methyl trans to N.13 The resonance due to the iminic activation, we tested the reaction of trifluorinated proton is also coupled with lg5Pt(3J(HPt)= ca. 50 Hz), ligands containing just one fluorine atom in an ortho thus showing the coordination of the ligand to platinum position such as 2,3,4- and 2,4,5-CsH2F3CH=NCHzCsH5 through the iminic nitrogen. For 3b, both the methyl (2a,b,respectively). For these ligands, both C-H and hydrogens and the methyl carbon are coupled with F5, C-F bond activations are plausible in principle. thus revealing a through-space interaction. In the 19F Previous work with related ligands has shown that NMR spectra, the resonances due to two (3c) or three the presence of a fluorine atom adjacent to the position (3a,b)aromatic fluorine atoms appear and the couplings to be activated can be decisive in the selectivity of this with lg5Ptare sensitive to the position of the fluorine process. For instance, it has been reportedlo that the in the ring, while the values of the coupling constants ligand 3-CsH4FCH=NCH2(2-CsH4C1) (2f) reacts with with other fluorine or hydrogen atoms in the aryl ring [PtzMe4@-SMe2)21via an ortho-metalation process in are in good agreement with the values reported in the which the C-H bond having a vicinal fluorine atom is 1iterat~re.l~ exclusively activated. For this reason, we also tested the difluorinated ligand ~ , ~ - C ~ H ~ F ~ C H = N C(2c). H & H H ~ Reactions with Triphenylphosphine. The reactions of compounds 3 with triphenylphosphine were It is interesting t o note that chelate-assisted oxidative studied, and the results are summarized in Scheme 2. addition of C-F bonds to tungsten(0) has been success3a,c reacted with PPh3 in a 1:lmolar ratio Compounds fully extended to monofluoro- and difluoro-substituted in acetone solution to yield the cyclometalated comaromatic rings of suitably designed 1igands.ll pounds [PtMe(2,3,4-CsHF3CH=NCH2CsH5)(PPh3)1(4a) and [PtMe(2,3-CsHzF2CH=NCH2CsH6XPP~)l (k), which Results result from a displacement reaction of SMez for PPh3. These compounds are yellow solids which were characPreparation of Platinum(I1) Cyclometalated terized by elemental analysis, IR, and lH, 19F,and 31P Compounds. The reaction of [PtzMe4@-SMe&I (1) NMR spectra. The presence of PPhs coordinated to with ligands 2a-c in acetone yielded the cyclometalated platinum is confirmed by IR and lH and 31P NMR platinum(I1)compounds [PtMe(RCH=NCH&&&&SMe2)1 spectra, while no signals are obtained for SMez in the (3;R = 2,3,4-CsHF3, 2,4,5-CsHF3, 2,3-CsH2Fd by ortho lH NMR. Both the methyl and the iminic groups are metalation with loss of methane, as shown in Scheme 1. The reaction is analogous to that reported for less (12) Benson, S. W. Thermochemical Kinetics; Wiley: New York, fluorinated derivatives such as the ligands 2d-g de1976. picted in Chart l and consists of an intramolecular (13)Crespo, M.; Puddephatt, R. J. Organometallics 1987, 6 , 2548. (11) (a) Lucht, B. L.; Poss, M. J.; King, M. A.; Richmond, T.G. J . Chem. Soc., Chem. Commun. 1991,400. (b)Richmond, T.G. Coord. Chem. Rev. 1990,195,221.
(14) (a) Paudler, W. W. In Nuclear Magnetic Resonance: General Concepts and Applications; Wiley: New York, 1987. (b) Crocker, C.; Goodfellow, R. J.; Gimeno, J.; U s h , R. J . Chem. SOC.,Dalton Trans. 1977, 1448.
Cyclometalated Pt(II) Compounds with Iminic Ligands
Organometallics, Vol. 14,No.1, 1995 357
Chart 1
p
denotes the activated bond upon reaction with (1)
(i) this work; (ii) ref. 10; (iii) ref. 17
coupled with lg5Ptand the values of the coupling constants are similar to those obtained for compounds 3. The methyl group appears as a doublet due to coupling with the phosphorus atom. Compounds 4a,c were also characterized crystallographically. Compound 3b,however, under similar reaction conditions, gave [PtMe(2,4,5-CsHF3CH=NCH2C6H5)(PPh3)21 (5b),together with decomposition products such as platinum( 0) and uncoordinated imine. Compound 5b, best obtained from reaction of 3b with 2 equiv of PPh3, is a white solid which was characterized by elemental analysis, IR, and lH, 19F,31P, and lg5PtNMR spectra. Spectral evidence points t o the presence of the iminic ligand acting in a monodentate fashion through the aryl carbon, as shown in Scheme 2. The presence of two coordinated PPh3 ligands is confirmed by the relative intensities of the signals in the lH NMR spectrum. The methyl resonance appears as a doublet of doublets; this pattern arises from coupling to two nonequivalent phosphorus atoms. The value of the coupling constant with platinum (smaller than for compound 3 or 4)is consistent with the presence of a phosphine ligand in a position trans t o the methyl group. Furthermore, the
iminic nitrogen is not coupled with lg5Pt and the methylene resonance appears as an A B quartet. The 31PNMR spectra show two sets of resonances due t o the nonequivalent phosphorus atoms, both coupled with platinum. In the I9FNMR spectrum, a dramatically large value (464Hz) is obtained for 3J(F5-Pt) in comparison to the values for cyclometalated compounds 3b (140 Hz) and 4b (87 Hz). Analogous values have been reported in the literaturel5 for the fluorine in ortho positions in (pentafluorophenyl)platinum(II) complexes. This large coupling constant in compound 5b may arise from a perpendicular orientation of the aryl group to the coordination plane. Consistently, the methyl group does not couple with the fluorine in position 5 of the aryl group, thus precluding an interaction as observed in 3b and 4b. Both 3J(F-Pt) and lJ(P-Pt) values for compound 5b were confirmed within experimental error by the lg5Pt NMR spectrum. d(lg5Pt)values are well within the (15)(a) FomiBs, J.; FortunB, J. C.; G6mez, M. A,; Menj6n, B.; Herdtweck, E. Organometallics 1993, 12, 4368. (b) Casas, J. M.; ForniBs, J.; Martin, A.; Menjh, B. Organometallics 1993, 12, 4376.
Crespo et al.
358 Organometallics, Vol. 14,No. 1, 1995
Scheme 2 1
PPhj (1 : 1)
I
range expected for organoplatinum(I1) compounds with phosphine ligands.16 When the reaction of compound 3b with PPh3 was carried out in acetone in the molar ratio 1:0.8,a mixture of 4b and 6b was formed, from which 4b was isolated in a pure form. NMR parameters for this compound are analogous to those obtained for 4a,c, except that the methyl group appears as a doublet of doublets due to coupling with both phosphorus and fluorine F5nuclei. Attempts to obtain the corresponding compounds 6a,c were unsuccessful, since the reaction of 3a or 3c with an excess of PPh3 yields 4a or 4c, which do not react further with PPh3. That is, for compounds 3a,c, the metallacycle is not cleaved upon reaction with PPh3. This behavior is analogous to that reported for [PtMe{ C~H~CH=NCHZ(~-C~H~C~))(PP~~)I.~'
The reaction of palladacycles with phosphines has been widely studied,18and depending on the nature of the cycle and the basicity of the nitrogen donor atom, cleavage of the metal-nitrogen bond may be achieved. However, in this system, a difference in reactivity toward PPh3 is observed for metallacycles of the same nature and it can only be attributed to the different substituents in the aryl ring. In particular, the presence of a fluorine atom in the position adjacent t o the PtC(ary1) bond (F5)seems to be decisive. In order to confirm this suggestion, we studied the reactions with PPh3 of monofluoro- and difluorosubstituted compounds such as 3d-f, previously obtained. The results are shown in Scheme 2. 3e, which (16)Benn, R.; Reinhard, R. D.; Rufinska, A. J. Organomet. Chem. 1986,282,291. (17)Crespo, M.;Font-Bardia, M.; Solans,X. J . Organomet. Chem., submitted for uublication. (18)Albert,'J.; mmez, M.;Granell, J.; Sales, J. Organometallics 1990,9,1405.
2
-
does not contain a fluorine atom in the position adjacent to the Pt-C(ary1) bond, reacted with only 1 equiv of PPb, even when an excess of phosphine was used. Compounds 3d and 3f, which do contain a fluorine substituent in such a position, reacted with 2 equiv of PPh3 to yield compounds 6d,f with cleavage of the metallacycle. Compounds 4d,f were easily obtained from reaction with 1 equiv of PPh3. A lower tendency to cleave the metallacycle is observed for less fluorinated compounds, 3d and 3f, than for the trifluorinated compound 3b. On the other hand, the presence of a chlorine atom in the benzyl ring for compounds 3d-f does not seem to be relevant. NMR parameters for compounds 4d-f and 5d,f, reported in the Experimental Section, are similar to those described above for compounds 4 and 6. lg5Ptand 19FNMR spectra of compound 6d are shown in Figure 1. The WP-Pt) parameters for compounds 4 are larger when a fluorine atom is present in position 5 of the aryl ring (compounds 4b,d,Q.These values increase gradually as the total number of fluorine atoms in the ring increases. A similar trend is observed for compounds 4a,c,e,although values are smaller. As a whole, WPPt) values decrease according to the sequence Ar = 2,4,5-CsHFs > 3,5-CsHzFz > 5-C&F > 2,3,4-&HF3 > 2,3-CsHzF2 > 2-CsH3F > c6&. It is illustrative to note that lJ(P-Pt) for 4a, containing the trifluorinated aryl group 2,3,4-C6HF3, is smaller (lJ(P-Pt) = 2387 Hz) than for 4f, containing the monofluorinated aryl group 5-CsH3F ('J(P-Pt) = 2479 Hz). The increase in lJ(P-Pt) values with increasing fluorination of the ring is consistent with a decrease in the trans influence of the aryl ring. WP-Pt) values can be rationalized in terms of the Fermi contact
Cyclometalated Pt(II) Compounds with Iminic Ligands
Organometallics, Vol. 14, No. 1, 1995 359 Table 1. Atomic Coordinates (x104) with Esd's in Parentheses for the Non-Hydrogen Atoms of 4a
a)
.I, u o u s Figure 1. (a) lg5Pt NMR spectrum of 5d. (b) 19F NMR spectrum of 5d (F5 region). -me
+ a
u
4
-ms
+ I
expression, which relates J to the electron density a t the coupled nu~1ei.l~The large inductive effect of fluorine substituents reduces the electron density on platinum, thus contracting the d orbitals and reinforcing the platinum-ligand bond in the trans position. The inductive effect must be more important for the fluorine F5 in a position ortho to the platinum. For compounds 5, values of 'J(PA-Pt) (PAtrans to aryl) follow the expected trend with increasing fluorination; however, no consistent trend is found for ~J(PBPt)values (PBcis to aryl). For compounds 5, a downfield shift of the iminic proton (6 9.00-9.52 ppm) related to compounds 4 is observed. As reported in the literature for several platinum compounds,20this shift implies a close vicinity between platinum and hydrogen atoms and can be explained by the existence of the weak three-centerfour-electron interaction C-H* *Pt2Irather than by the paramagnetic anisotropy of the metal. On the other hand, the large 3J(F5-Pt)values could be indicative of a Pt. *F5interaction. These two observations suggest apical Pt- *H and Pt. *F5interactions in the formally square-planar compounds 5. A similar situation has been detected crystallographically for a related palladium compound.22 Structures of Compounds 4a and 4c. The crystal structures are composed of discrete molecules separated by van der Waals distances. Crystallographic data are given in the Experimental Section, atomic coordinates are in Tables 1 and 2, and selected bond distances and angles are listed in Tables 3 and 4. The structures are (19) Pregosin, P. S.;Kunz, R. W. In 32Pand 13C NMR of Transition Metal Phosphine Complexes; Diehl, P., Fluck, E., Kosfeld, R., Eds.; Springer-Verlag: Berlin, 1979; pp 42-45. (20) (a) Albinati, A.; Pregosin, P. S.; Wombacher, F.Znorg. Chem. 1990,29,1812. (b) Albinati, A.; Anklin, C. G.; Ganazzoli, F.;Riiegg, H.; Pregosin, P. S. Znorg. Chem. 1987,26, 503. (c) Albinati, A.; Arz, C.; Pregosin, P. S. I n o g . Chem. 1987,26,508. (21) Brammer, L.; Charnock, J. M.; Goggin, P. L.; Goodfellow, R. J.; Orpen, A. G.; Koetzle, T. F. J. Chem. SOC.,Dalton Trans. 1991, 1789. (22) Albert, J.; Granell, J.; Moragas, R.; Sales, J.; Solans, X. J. Organomet. Chem., submitted for publication.
X
V
7
4052(1) 2364(2) 4467(5) 7540(6) 8311(6) 7245(5) 5473(6) 6069(8) 7015(7) 7408(9) 6853(11) 5919(7) 5317(7) 3920(7) 4000(7) 3193(8) 3328(12) 4206(16) 5034(13) 4926(7) 3995(8) 2429(6) 184l(9) 2022(9) 2697(10) 3279( 10) 3175(8) 1519(7) 1036(11) 346(8) 136(8) 638(12) 1249(7) 1379(7) 329(8) -434(9) -84(9) 925(13) 1684(8)
1208(1) 914(1) 205 l(4) 1087(4) 2178(4) 2777(3) 1430(5) 1139(5) 1420(7) 1913(6) 2256(7) 1990(6) 2306(5) 2301(4) 1869(5) 1879(4) 1482(8) 1143(10) 1103(6) 1533(6) 361(4) 150(4) -356(5) -904(7) -871(6) -355(7) 136(5) 1377(5) 1156(5) 1577(7) 2119(6) 2351(7) 1929(6) 798(5) 662(7) 604(8) 743(7) 891(8) 9435)
2389(1) 1454(2) 1469(6) 6100(7) 5403(7) 3317(7) 3431(7) 4486( 10) 5 10 1( 10) 4779(11) 3709( 12) 3075(9) 1976(8) 230(8) -876(8) -1889(7) -297 1( 12) -2993(18) - 1928( 13) -933(8) 3389(8) 629(7) 868(9) 197(11) -791(11) -968( 14) -306(11) 274(9) -942( 11) -17 18( 12) - 1385(15) -226( 13) 602(9) 2607(9) 2254(11) 3090( 13) 4349(10) 4783(15) 3859(10)
shown in Figure 2 and 3 and confirm the geometry predicted from spectroscopic studies. In particular, the C=N group is endo to the cycle and the methyl group is trans to the nitrogen atom. In both compounds, the coordination sphere of platinum is square planar with a tetrahedral distortion. The following displacements (A) are observed from the least-squares plane of the coordination sphere for 4a: Pt, -0.001; P, 0.077; N, -0.086; C(1), 0.105; C(15), -0.094. Displacements for 4c are as follows: Pt, 0.017; P, 0.084; N, -0.111; C(l), 0.116; C(15), -0.107. The metallacycles are approximately planar; the largest deviation from the mean plane determined by the five atoms is -0.022 A for C(1) in 4a and 0.029 for C(1) in 4c. The angle between the metallacycle and the coordination planes is 4.6"for 4a and 5.3" for 4c. The angles between adjacent atoms in the coordination sphere of platinum lie in the range 107.4(2)78.4(4)"for 4a and 98.5(2)-77.5(2)' for 4c, the smallest angles corresponding to the metallacycle. Pt-N and Pt-C(ary1) bond lengths in 4a,c are well within the range of values obtained for cyclometalated platinum(11),23924p l a t i n ~ m ( I V ) , ~ pand ~ , ~palladium(II)26 ,~~ com-
A
(23)(a) Stoccoro, 6.;Cinellu, M. A.; Zucca, A.; Minghetti, G.; Demartin, F. Znorg. Chim. Acta 1994,215, 17. (b) Canty, A. J.; Minchin, N. J.;Patrick, J. M.; White, A. H.J.Chem. SOC.,Dalton Trans. 1983,1253. (24) Navarro-Ranninger,C.; L6pez-Solera, I.; Alvarez-ValdBs, A.; Rodrfguez-Ramos,J. H.; Massaguer,J. R.; Garcfa-Ruano,J. L.; Solans, X. Organometallics 1993,12, 4104.
Crespo et al.
360 Organometallics, Vol. 14, No. 1, 1995 Table 2. Atomic Coordinates (xlp)with M ’ s in Parentheses for the Non-Hydrogen Atoms of 4c X
3206(1) 2054(1) 6189(4) 4432(4) 2630(4) 4295(6) 5234(6) 5908(7) 5618(6) 4726(6) 4089(5) 3156(6) 1683(6) 739(5) -276(7) - 1123(7) -920(9) 104(10) 910(7) 3787(8) 2488(6) 2002(7) 2337(9) 3222(8) 3762(8) 3372(7) 386(6) -415(6) -1649(6) -2122(8) -1348(7) -98(6) 2130(6) 3227(6) 3395(7) 2424(9) 1328(10) 1154(7)
Y
2222(1) 3431(1) -1333(3) - 1463(3) 1026(4) 1126(4) 1172(5) 396(7) -527(6) -540(6) 268(6) 229(6) 1014(6) 19(5) -65(7) -976(7) -1713(6) -1628(7) -796(5) 3091(6) 3841(6) 4691(7) 4963(5) 4510(6) 3779(8) 3390(5) 2970(5) 3032(6) 2652(7) 2207(8) 21 17(6) 2514(7) 4670(6) 5332(5) 6196(7) 6523(8) 5839(8) 4973(6)
Table 3. Selected Bond Lengths (A) and Angles (deg) for Compound 4a
Z
103(1) -1797(2) 4399(5) 1570(6) -1 165(6) 1623(10) 3117(8) 4025(9) 3496(8) 2034(8) 1188(7) -384(8) -2746(8) -2800(7) -2466(8) -2564( 11) -2975( 10) -3331(9) -3237(8) 1722(10) -3459(7) -4715(9) -5901(10) -5987(9) -4865( 10) -3527(8) -25 1O(8) -3994(8) -4446(11) -3359(13) -1783(10) -1397(9) -1436(8) -1095(9) -653(11) -582(13) -767( 13) - 1273(10)
P-Pt N-Pt C(l)-Pt C(15)-Pt C(16)-P C(22)-P C(28)-P ~(3)-~(1) ~(4)-~(2) C(5)-F(3) N-Pt-P C(l)-Pt-P C(1)-Pt-N C(15)-Pt-P C(15)-Pt-N C( 15)-Pt-C(1) C( 16)-P-Pt C(22)-P-Pt C(22)-P-C(16) C(28)-P-Pt C(28)-P-C(16) C(28)-P-C(22) C(7)-N-Pt C(8)-N-Pt C(8)-N-C(7) C(2)-C(l)-Pt C(6)-C( 1)-Pt C(6)-C( 1)-C(2) C(3)-C(2)-C( 1) C(4)-C(3)-C(2) C(4)-C(3)-F(l)
Bond Lengths 2.303(2) C(6)-C( 1) 2.156(8) c(3)-c(2) 2.026(8) C(4)-C(3) 2.118(9) C(5)-C(4) 1.873(9) C(6)-C(5) 1.826(10) C(2)-C(1) 1.843(9) C(7)-C(6) 1.371(14) C(8)-N 1.360(11) C(9)-C(8) 1.31(2) C(7)-N Bond Angles 107.4(2) F(l)-C(3)-C(2) 172.5(2) C(3)-C(4)-F(2) 78.4(4) C(3)-C(4)-C(5) 83.6(3) F(2)-C(4)-C(5) 168.1(3) F(3)-C(5)-C(6) 91.0(4) F(3)-C(5)-C(4) 110.6(2) C(6)-C(5)-C(4) 124.1(3) C(5)-C(6)-C(l) 103.0(4) C(5)-C(6)-C(7) 113.9(3) C(l)-C(6)-C(7) 104.6(5) N-C(7)-C(6) 98.3(4) C(9)-C(8)-N 114.7(6) C(lO)-C(9)-C(8) 125.9(5) C(14)-C(9)-C(8) 118.9(8) C(17)-C( 16)-P 131.7(8) C(21)-C(16)-P 114.2(7) C(27)-C(22)-P 114.1(8) C(23)-C(22)-P 120.1(11) C(33)-C(28)-P 125.6(12) C(29)-C(28)-P 119.5(10)
1.40(2) 1.412(14) 1.24(2) 1.45(2) 1.396(14) 1.406(13) 1.467(14) 1.495(10) 1.502(14) 1.256(11) 114.8(12) 124.4(11) 119.0(10) 116.5(10) 121.7(13) 12 1.4(10) 116.8(12) 124.4(11) 120.1(12) 115.5(8) 117.0(10) 112.5(7) 118.6(9) 119.8(7) 124.9(7) 113.8(6) 118.2(7) 124.7(8) 118.1(7) 123.4(8)
Table 4. Selected Bond Lengths (A) and Angles (deg) for Comwund 4c P-Pt N-R C(l)-Pt C(15)-Pt C(16)-P C(22)-P C(28)-P ~ ( 4 1 - 3 1) ~(5)-~(2) C(7)-N
Bond Lengths 2.299(2) C(6)-C(1) 2.153(5) c(3)-c(2) 2.05 l(7) C(4)-C(3) 2.046(8) C(5)-C(4) 1.805(6) C(6)-C(5) 1.837(6) C(2)-C( 1) 1.814(7) CU)-C(6) 1.330(8) C(8)-N 1.387(9) C(9)-C(8) 1.275(9)
1.302(9) 1.358(11) 1.421(12) 1.381(10) 1.360(10) 1.429(10) 1.479(8) 1.485(8) 1.548(9)
Von Zelewsky has reported that Pt-N and Pt-C bond lengths are similar for platinum(I1) and platinum(rV) complexes due t o the similar radii of square-planar Pt(I1)and octahedral Pt(IVh4 Moreover, Navarro-Ranninger has reported similar M-C and M-N bond distances for palladium(I1) and platinum(11) cyclometalated compounds.24 The iminic bond Bond Angles distances are within the range observed for analogous N-Pt-P 98.5(2) C(3)-C(4)-F(l) 120.2(6) cyclometalated palladium(II)26and ~ l a t i n u m ( I 1com)~~ C(1)-Pt-P 173.8(2) C(5)-C(4)-F(l) 122.7(6) C(1)-Pt-N 77.5(2) C(5)-C(4)-C(3) 117.1(7) pounds. C( 15)-Pt-P 92.5(2) C(4)-C(5)-F(2) 115.7(6) A comparative study of structural features for the C(15)-R-N 167.3(3) C(6)-C(5)-F(2) 122.6(6) platinum(I1) compounds 4a,c and the previously reC(15)-R-C( 1) 92.1(3) C(6)-C(5)-C(4) 121.3(7) ported platinum(I1) [PtMe{CSH~CH=NCH~(~-C~H~CI))C(16)-P-Pt 112.2(3) C(5)-C(6)-C(l) 124.4(6) C(22)-P-Pt 113.0(2) C(7)-C(6)-C(1) 115.9(7) (PPhdl (4g) and platinum(IV1 [PtMe2C1(2-C&C1C(22)-P-C(16) 106.6(3) C(7)-C(6)-C(5) 119.5(7) C H = N C H ~ C ~ H ~ ) ( P P(6) ~ Scompounds )] is reported in C(28)-P-Pt 120.5(2) C(6)-C(7)-N 117.3(6) Table 5. An analysis of these values reveals that Pt-N C(28)-P-C( 16) 100.0(3) C(9)-C(8)-N 112.2(6) and Pt-P bond lengths for fluorinated compounds 4a,c C(28)-P-C(22) 102.9(3) C(lO)-C(9)-C(8) 121.0(7) are longer and shorter, respectively, than for 4g. C(7)-N-Pt 119.7(6) 113.0(4) C(14)-C(9)-C(8) C(8)-N-Pt 128.1(5) C(17)-C(16)-P 121.9(5) However, no significant differences in these parameters C(8)-N-C(7) 118.8(5) C(21)-C(16)-P 120.5(6) are found between 4a and 4c. Similarly, Pt-Me, cis to C(2)-C( 1)-Pt 128.3(5) C(23)-C(22)-P 127.9(6) C(aryl), bond distances are longer for 4a,c than for 4g. C(6)-C( 1)-Pt 116.1(5) C(27)-C(22)-P 115.6(5) These results suggest that the electron-withdrawing C(6)-C( 1)-C(2) 115.6(6) C(29)-C(28)-P 120.5(5) C(3)-C(2)-C(l) 123.3(7) C(33)-C(28)-P 123.8(5) ability of the fluorinated rings produces stronger Pt-P C(4)-C(3)-C(2) 118.2(6) bonds in trans, and weaker Pt-N and Pt-Me bonds in cis. We are tentative, however, about drawing conclu(25) (a) van Koten, G.; Terheiden, J.;van Beek, J. A. M.; Wehmansions from these structural values, since the differences Ooyevaar, I. C. M.; Muller, F.; Stam, C. H. Orgunonetullics 1990,9, in bond lengths are small and may be attributed to 903. (b) van Beek, J. A. M.; van Koten,G.; Wehman-Ooyevaar, I. C. M.; Smeets, W. J. J.;van der Sluis,P.; Spek, A. L. J.Chem. Soc.,Dalton packing effects rather than to electronic effects. For Trans. 1991, 883. (X= C1, Br; Y instance, for trans-[PtX(CsH4Y)(PEt3)21 (26)Albert, J.; Ceder, R. M.; G6mez, M.; Granell, J.; Sales, J. Organometallics 1992, 11, 1536. = p-NMe2, p-CF3, p-COzMe, H, m-CN, m-NMez) elec-
Cyclometalated Pt(II) Compounds with Iminic Ligands
Organometallics, Vol. 14, No. 1, 1995 361
Table 5. Bond Distances (A)and Bond Angles (deg) for Cyclometalated Platinum(II)(4) and Platinum(1V) (6) Compounds of N-Benzylidenebenzylamines CI
4
compd"
R-C,1
Pt-CH3
[PtMe(C&F,CH=NR)(PPhs)l
(4a)
[PtMe(C6HzFzCH=NR)(Pph3)1(4c) [PtMe(C&CH=NR)(PPh3)] (4g)b
[PtMezCl(C6H3ClCH=NR)(PPh3)](6)' a
0
2.1 18(9) 2.046(8) 2.010( 12) 2.097( 2.048(9)'
4a, 4c,and 6, R = CHzC&Is; 4g, R = CH2(2-C&Cl).
Pt-N
2.026(8) 2.05 l(7) 1.973(10) 2.027( 10)
2.156(8) 2.153(5) 2.090(7) 2.152(7)
R-P 2.303(2) 2.299(2) 2.334(3) 2.43l(2)
C=N
NPtCnqI
1.256(11) 1.275(9) 1.307(14) 1.291(11)
78.4(4) 77.5(2) 79.3(5) 80.4(4)
Taken from ref 17. Taken from ref 8. Me,. Meb.
ti261
ti20
ti121
Cll3)
Fill
Figure 3. View of the structure of 4c.
Figure 2. View of the structure of 4a.
tronic effects of the substituents do not cause observable changes in the Pt-P bond lengths, although changes in WPt-P) were observed.27
Discussion The results show that in [PtMe(RCH=NCHzCeHs)(SMe2)I the metallacycle can be cleaved by an excess of PPh3 only if there is a fluorine atom in a position adjacent to the Pt-C(ary1) bond (position 51, irrespective of the fluorination of the ring, which is not decisive. Unfortunately, no crystal structures of compounds 4 or 5 containing fluorine F5 were obtained. However, spectroscopic data for these compounds are informative of the combined effects leading t o a higher reactivity for ortho-platinated compounds bearing a fluorine adjacent to platinum. The study of lJ(P-Pt) values for compounds 4 reported in the previous section show that the electronwithdrawing ability of the aryl ring is more sensitive to the presence of a fluorine atom adjacent t o platinum (27)Amold, D. P.; Bennett, M. A. Znorg. Chem. 1984,23,2117.
than to the total fluorination of the ring. This suggests that the presence of fluorine F5 modifies the electronic distribution in the coordination sphere of platinum. Furthermore, the basicity of the iminic nitrogen decreases and, as a result, cleavage of the Pt-N bond occurs more readily. On the other hand, steric repulsion between the methyl group and F5may account for the easier formation of compounds 5 when fluorine F5, adjacent to platinum, is present. "he chelating nature of the iminic ligand in compounds 4 implies that F5 should be in the coordination plane and, as reported above, it is coupled with the methyl group. Molecular models for compound 4b,based on the crystal structure of compound 4a, give a C* *Fdistance of 2.617 A. An analogous value (C- -F = 2.773 A) has been found in the molecular structure of C ~ R ~ ( P M ~ ~ ) ( Vand ~ -this C ~value F ~ )has , ~ been ~ taken as an indication of a short contact between the methyl group and the fluorine, which are close enough for the van der Waals radii to overlap. Formation of compounds 5 with cleavage of the metallacycle would relieve the steric crowding in the coordination sphere of platinum. It seems surprising that platinum(IV) metallacycles containing a pentafluorophenyl group such as [PtMenF(CsF&H=NCH2C6H5)(SMe2)] could not be cleaved
-
(28) Belt, S.T.; Helliwell, M.; Jones, W. D.; Partridge, M. G.; Perutz, R. N. J . Am. Chem. SOC.1993,115, 1429. (29) Schmulling, M.; Ryabov, A. D.; van Eldik, R. J. Chem. SOC., Chem. Commun. 1992, 1609.
362 Organometallics, Vol. 14, No. 1, 1995 with PPh3.8 This could be explained by the higher affinity of platinum(lV) for nitrogen donor ligands when compared to platinum(I1). It is also worth noticing that, in octahedral platinum(IV) compounds, apical Pt- *F and Pt- *Hinteractions, as described for compounds 5 in the previous section, would be hindered. Although the main driving forces for the cleavage of the metallacycle are the stereoelectronic effects arising from the presence of F5, the weak apical interactions may also account for the easy formation of compounds 5.
Conclusions The reaction of [Pt~,Me4(p-SMez)zl(1) with di- or trifluorinated iminic ligands containing both C-F and C-H bonds in ortho positions produces exclusively C-H bond activation. We have reported elsewherelo that the presence of a fluorine atom adjacent to the C-H bond to be activated in the iminic ligand is decisive in the selectivity of the metallacycle formation. The results reported here show that the position adjacent t o the Pt-C(ary1) bond in platinum(I1) metallacycles is also strategical in the cislabilization effect of the aryl group. Thus, the electronic and steric effects arising from the presence of a fluorine atom in this position have a more important effect on reactivity than the increase in fluorination. For both platinum(I1) and palladium(II), five-membered endo metallacycles are among the most stable. Nevertheless, platinacycles can be cleaved under mild conditions, provided that a fluorine atom is present in position 5. It has been shown that the reactivity of platinum(I1) and palladium(I1) complexes can be tuned by steric or electronic effect^;^' the results reported in this paper are a further example of reactivity tuning in platinum compounds.
Experimental Section 'H, 31P(1H},19F,13C, and l g 5 P t NMR spectra were recorded by using Varian Gemini 200 (lH, 200 MHz), Bruker WP80SY (31P, 32.4 MHz), and Varian XI, 300FT (19F, 282.2 MHz; 13C, 75.43 MHz; 31P, 121.4 MHz; lg5Pt,64.19 MHz) spectrometers and are referenced to SiMe4 (lH, 13C),H3P04 (31P),CCLF (19F), and H2PtC16in D2O (lg5Pt). 6 values are given in ppm and J values in Hz. Microanalyses were performed by the Institut de Quimica Bio-OrgBnica de Barcelona (CSIC) and by the Serveis Cientifico-Tecnics de la Universitat de Barcelona. Preparation of Compounds. The complex [PtzMerhSMe2)zI (1)was prepared by the literature method.30 Compounds 2 were prepared by reaction of 5 mmol of the corresponding aldehyde with an equimolecular amount of the benzylamine in ethanol. The mixture was refluxed for 2 h, and the solvent was removed in a rotary evaporator to yield yellow oils. 2,3,4-C&FsCHNCHzC&~ (2a). lH NMR (CDC13): 6 4.87 [s,CH21,8.63[s,CHN] (7.01 [m], 7.81 [ml, 7.33 [ml, aromatics}. 19FNMR (CDC13): 6 -137.17 [dd, 3J(F2F3) = 21, 4J(F2F4) = 9, = 3J(F4H5)= 9, F41, F2], -149.50 [dt, 4J(F4F3)= 21, 4J(F4F2) -167.42 [dt, V(F2F3)= 3J(F4F3)= 21, 4J(F3H5)= 6, F31. 2,4,6-C&F&HNCH&J& (2b). 'H NMR (CDC13): 6 4.85 [s,CHd, 8.60 [s,CHN] (6.96 [m], 7.33 [ml, 7.90 [ml, aromatics}. = 3J(F2H)= 15, 19FNMR (CDC13): 6 -130.25 [td, 4J(F2F4) 5J(F2F5)= 6, F2], -135.62 [dt, 3J(F4F5)= 21, 'J(F5F2)= 4J(F5H3)= 6, F51, -148.35 [m, F41. P,S-C&FzCHNCHaC&Itj ( 2 ~ ) .'H NMR (CDC13): 6 4.87 [s,CH21,8.63[s,CHN1(7.01 [ml, 7.33 [ml, 7.81 [ml, aromatics}. (30)Scott, J. D.;Puddephatt, R.J. Organometallics 1983,2,1643.
Crespo et al.
"F NMR (CDCl3): 6 -145.32 [dt, J(FF) = 18, J(FH) = 61, -153.72 [dt, J(FF) = 18, J(FH) = 61. Compounds 3 were prepared by reaction of 100 mg (0.17 mmol) of [PtzMe4@-SMez)2] (1) with 0.35 mmol of the corresponding imine in acetone. The mixture was stirred for 16 h, and the solvent was removed in a rotary evaporator. The residue was washed in hexane and recrystallized in acetonel hexane to yield yellow-orange solids, which were filtered and washed with hexane. [ P ~ M ~ ( ~ , ~ , ~ - C ~ H F S C H H ~ C ~ HYield ~ ) ( S70 M~~)I(~~) mg (77%). Mp: 141 "C dec. Anal. Calcd for C I ~ H ~ S F ~ N S P ~ : C, 39.24; H, 3.49; N, 2.69. Found: C, 39.17; H, 3.63; N, 2.58. 1H NMR (acetone&): 6 0.80 [s, 2J(HPt) = 82, Me], 1.97 [s, 3J(HPt) = 30, SMez], 5.29 [s, 3J(HPt) = 13, CHd, 9.10 [s, V(HPt) = 56, CHN] (7.15 [m], 7.31 [ml, aromatics}. l9FNMR (acetone-ds): 6 -173.71 [td, 5J(F3Pt)= 10, V(F3F2)= 3J(F3F9 = 19, 4J(F3H5)= 7, F3], -141.62 [dd, 4J(F2Pt) = 46, 3J(F2F3) = 19, 4J(F2F4)= 7, F2], -133.86 [m, 4J(F4Pt)= 58, 3J(F4F3) = 19, 3J(F4H)= 11, 4J(F4F2) = 7, F41. 13CNMR (acetone-&): 6 -12.73 [s, IJ(CPt) = 791, Me], 19.69 [s, SMezI, 62.96 Is, CHz1, 114.78 [d, 2J(CF)= 9, %T(CPt)= 97, C5 in C6HF31 (128.10 [SI, 128.35 [SI, 129.19 [SI, aryl carbons in C6H5}, 138.33 [s, C6 in CtjHF31, 169.55 [s, 'J(CPt) = 82, C m ] . [ P ~ M ~ ( ~ , ~ , S - C ~ H F ~ C H H ~ C ~ H ~Yield ) ( S M75~ Z ) I ( ~ ~ ) . mg (83%). Mp: 145 "C dec. Anal. Calcd for C17H1sF3NSPt: C, 39.24; H, 3.49; N, 2.69. Found: C, 39.45; H, 3.70; N, 2.62. IH NMR (acetone-ds): 6 1.15 [d, WHPt) = 80, 5J(HF5) = 6, Me], 1.94 [s, V(HPt) = 33, SMe21,5.25 Is, WHPt) = 13, CH21, 9.18 [s, 3J(HPt) = 55, CHN] (6.8 [ml, 7.31 [ml, aromatics}. 19FN M R (acetone&): 6 -130.78 [M,V(F5Pt)= 140.4,3J(F5F9 = 5J(F5F2) = 18, 4J(F5H3)= 6, F5], -129.65 [dt, 4J(F4Pt)= 128, 3J(F4F6) = 18,4J(F4F2) = 3J(F4H) = 6, F4], -120.62 [dd, 4J(F2Pt) = 67, V(F2F5)= 18, 4J(F2F4) = 6, F21. 13CNMR (acetone&): 6 -22.18 [d, 4J(CF) = 17, lJ(CPt) = 715, Me], 19.82 [s, SMez], 63.20 [s, CHz], 101.041 [t, 2J(CF)= 24, C3 in CsHF31 (128.75 [SI,128.97 [SI,129.90 [SI,aryl carbons in C6H5}, 139.13 [s, 1J(CPt) = 1064, C6 in CsHF3],171.23 [s, zJ(CPt)= 83, CHNI. [PtMe(2,3-CsH2F2CHNCH2C&)(SMe2)](3c). Yield: 70 mg (80%), Mp: 159 "C dec. Anal. Calcd for C17H1gF2NSPt: C, 40.69; H, 3.81; N, 2.79. Found: C, 39.58; H, 3.97; N, 2.65. 'H NMR (acetone-ds): 6 0.84 [s, %T(HPt)= 82, Me], 1.97 [s, 3J(HPt) = 28, SMe21, 5.29 [s, 3J(HPt) = 13, CH21, 9.15 [s, 3J(HPt)= 56, CHN], 7.30 [m, aromatics]. 19FNMR (acetone&): 6 -145.81 [dd, 4J(F2Pt) = 49, 3J(F2F3) = 18, *J(F2H)= 6, F2], -151.29 [m, 3J(F3F2) = 18, V(F3H4)= 12, 4J(F3H5)= 6, F3]. 13C NMR (acetone-ds): 6 -13.30 [s, 'J(CPt) = 797, Me], 19.56 [s, SMe2],63.01 [s, CHz], 120.28 [d, 2J(CF)= 15, zJ(CPt) = 87, c5in CsHFs] (128.05 [SI, 128.36 [SI, 129.16 [SI, aryl carbons in C&} (131.49 [SI, 138.45 [SI,aryl carbons} 170.02 [s, 2J(CPt) = 87, CHNI. 4a was prepared by reaction of 50 mg (0.096 mmol) of 3a with an equimolar amount of PPh3 in acetone. The mixture was stirred at room temperature for 2 h. On addition of hexane, yellow crystals were formed, and they were collected by filtration, washed with hexane, and dried in vacuo. 4c-f were prepared by an analogous procedure from the corresponding compounds 3. Compound 4b was best obtained by crystallization from the reaction mixture of 3b with less than the equimolar amount of P P b . Suitable crystals for crystallographic analyses of 4a,c were grown by slow evaporation from an acetone-hexane solution. 6b was prepared by reaction of 50 mg (0.096 mmol) of 3b with 2 equiv of PPh3 in acetone. Within 1h, the color of the solution faded and a white precipitate was formed. After addition of hexane, the white solid was collected by filtration, washed with hexane, and dried in vacuo. Compounds 5d,f were prepared by an analogous procedure from the corresponding compounds 3. [P~M~(~,~,~-C,JHF~CHNCH~C&)(PP~S)~ (4a). Yield 50 mg (72%). Mp: 182 "C dec. Anal. Calcd for C33H27F3NPPt: C, 55.00; H, 3.78; N, 1.94. Found: C, 55.07; H, 3.77; N, 1.93. 'H NMR (acetone-&): 6 0.61 [d, 'V(HPt) = 83, 3J(HP) = 7,
Organometallics, Vol. 14, No. 1, 1995 363
Cyclometalated Pt(II) Compounds with Iminic Ligands
Table 6. CrystallographicData and Details of the Me], 4.38 [s, 3J(HPt) = 10, CHz], 8.80 [s, 3J(HI't) = 56, CHNI Refinements for Compounds 4a,c (6.80 [m], 7.19 [m], 7.42 [m[, 7.60 [ml, aromatics}. 19FNMR (acetone-&): 6 -172.67 [td, 3J(F3F2)= 3J(F3 F2) = 19, 4a 4c 4J(F3H5)= 7, F3], -141.62 [dt, 4J(F2Pt)= 51, 3J(F2F3) = 19, formula C33H28FN'Pt C33Hz7F3wPt 4J(F2F4)= 5J(F2H5)= 7, F2], -133.43 [m, 4J(F4Pt)= 69, PI. 702.66 720.67 fw 31PNMR (acetone): 6 28.66 [s, lJ(PR) = 23871. trislinic monoclinic cryst syst [PtMe(2,4,5-C&IFsCHNCH~C~)(PP~)1 (4b). Mp: 197 P1 P21Ic space group "C dec. Anal. Calcd for C ~ ~ H Z ~ F ~ C, N P55.00; P ~ : H, 3.78; N, 12.03l(2) 12.475(3) a, A 13.757(2) 21.642(5) 1.94. Found: C, 54.98; H, 3.76; N, 1.85. lH NMR (acetoneb, A 9.768(2) 10.497(2) c, A de): 6 0.99 [dd, WHPt) = 87, 3J(HP) = 9, 5J(HF5)= 6, Me], 72.9l(2) 90 a, deg 4.27 [s,3J(HPt)= 11,CHz], 8.82 [s,3J(HPt) = 54, CHNI. 19F 114.91(1) 96.92(2) P, deg NMR (acetone-&): 6 -120.78 [m, 4J(F2Pt)= 63, 4J(F2F4)= 104.20(2) 90 deg 10, 5J(F2F5)= 20, 3J(F2H)= 8, F21, -129.11 [m, 4J(F4Pt)= 1387.7(7) 2813.4(11) v, A3 104, 3J(F4F5) = 20, 4J(F4F2)= 3J(F4H)= 10, WF4Ha)= 5, F41, 1.681 1.703 Dc, g cm-3 -130.94 [m, SJ(F5Pt) = 87, 3J(F5F4) = 5J(F5F2) = 20, 4J(F5H3) 4 2 2 = 5J(F5Me)= 6, F5]. 31PNMR (acetone): 6 27.16 [s, lJ(PR) 1412.0 688.0 WW 0.1 x 0.1 x 0.2 0.1 x 0.1 x 0.2 = 26511. cryst size, mm3 54.14 53.49 p(Mo Ka), cm-' [P~M~(~,~-C~H~F&HNCHZC&IS)(PP~S)I ( 4 ~ )Yield: . 57 0.710 69 0.710 69 A(Mo Ka), 8, mg (81%). Mp: 189 "C dec. Anal. Calcd for C33HzsFzNPPt: 298 293 T,K C, 56.41; H, 4.02; N, 1.99. Found: C, 56.42; H, 3.99; N, 1.98. 5677 5140 no. of rflns collected lH NMR (acetone-de): 6 0.65 [d, V(HPt) = 83, 3J(HP) = 7, 0.031 0.048 R Me], 4.40 [s, 3J(HPt) = 10, CHz], 8.82 [s, 3J(HPt)= 56, CHNI 0.078 0.112 RdP) (6.85 [ml, 7.19 [m], 7.41 [m], 7.61 [ml, aromatics}. 19FNMR 346 354 no. of refined params (acetone-de): 6 -146.47 [dt, 4J(F2Pt)= 38, 5J(F2P)= 4J(F2H) 0.1 0.1 max shift/esd +0.4 and -0.4 +1.7 and -1.3 = 7, 3J(F2F3)= 19, F2], -150.49 [m, 3J(F2F3) = 19, 3J(F3H4)= max and min diff peaks, e A-3 11,4J(F3H)= 5, F3]. 31P NMR (acetone): 6 29.18 [s, lJ(PR) = 22941. = 15, CHZ,AB pattern}, 9.50 [s, CHNI, 6.10 [m, CeHzFzl(7.00 [ P ~ M ~ ( ~ , ~ - C ~ ~ I ~ Z C H N C H Z ( ~ - C ~(4d). H ~ CYield ~ ) ) ( P P ~[m], S ) ] 7.15 [ml, 7.35 [m], aromatics}. 19FNMR (acetone-&): 6 46.0 mg (70%). Mp: 162 "C dec. Anal. Calcd for C33H27-88.85 [m, 3J(F5Pt)= 371, 4J(F5P)= 13, 3J(F5H4)= 4J(F5F3) ClFZNPPt C, 53.77; H, 3.69; N, 1.90. Found: C, 53.88; H, = 7, F51, -124.72 [m, F21. 31PNMR (acetone): 6 24.16 [t, WPA3.81; N, 1.86. lH NMR (acetone-de): 6 1.01 [dd, V(HPt) = pt) = 2234, 'J(PAPB)= 4J(P~F5) = 14, PA],23.07 [d, 'J(PBP~) 83, 3J(HP)= 9, 5J(HF5)= 6, Me], 4.29 [s, 3J(Hpt)as shoulders, = 1928, 2 J ( P ~ P=~14, ) PB]. lg5PtNMR (acetone): 6 -4630.59 CHz], 8.57 [s, 3J(HPt) = 54, CHN] (6.75 [ml, 7.17 [ml, 7.41 [m, 'J(Pt-PA) = 2238, 'J(Pt-PB) = 1916, 3J(Pt-F5) = 3711. [m], 7.67 [m], aromatics}. 19F NMR (acetone-&): 6 -94.55 [P~M~(S-C~H~FCHNCHZ(~-C&C~)}(PP~&I (50. Yield: [m, 3J(F5Pt)= 62, F5], -121.26 [m, F3]. 31PNMR (acetone): 50 mg (53%). Mp: 152 "C dec. Anal. Calcd for C51H43ClFNPz6 28.00 [s, lJ(PPt) = 25491. Pt: C, 62.41; H, 4.42; N, 1.40. Found: C, 61.98; H, 4.20; N, [PtMe{2-C&FCHNCHg(2-C&Cl)}(PPhs)l (4e). Yield: 1.41. lH NMR (acetone-&): 6 0.26 [dd, zJ(HR)= 65, 3 J ( H P ~ ) 49.9 mg (72%). Mp: 167 "C dec. Anal. Calcd for C33H28= 9, 3 J ( H P ~= ) 6, Me] (4.81 (d), 4.94 (d), %J(HH) = 15, CHZ, ClFNPR: C, 55.12; H, 3.92; N, 1.95. Found C, 55.51; H, 3.90; AB pattern}, 9.52 [s, 3J(HPt) = 9, CHN] (6.60 (m), 6.30 (m), N, 2.02. lH NMR (acetone-de): 6 0.75 [d, zJ(HPt)= 83, 3J(HP) CGH~F} (7.06 [m], 7.24 [m], 7.36 [m], aromatics}. 19FNMR = 8, Me], 4.44 [s, 3J(HPt) = 10, CHz], 8.75 [s, 3J(HPt) = 55, (acetone-&): 6 -92.51 [m, 3J(F5R) = 377, 4J(F5P) = 13, CHNI (6.75 [ml, 7.25 [ml, 7.44 [ml, 7.69 [ml, aromatics}. l9F 3J(F6H4)= 6, F5]. 31P NMR (acetone): 6 24.13 [t, 'J(pApt) = NMR (acetone-de): 6 -119.92 [dd, 4J(F2Pt)= 46, 3J(F2H3)= 2175, 'J(P.&) = 4 J ( P ~ F 5=) 14, PA],23.17 [d, 'J(P&) = 1930, 15, 4J(F2H4)= 9, FZ]. 31PNMR (acetone): 6 28.97 [s, 'J(PPt) 'J(PAPB) = 14, PB]. 1g5PtNMR (acetone): 6 -4627.20 [m, = 22461. 'J(Pt-PA) = 2202, 'J(P~-PB)= 1930, 3J(Pt-F5)= 3771. [PtMe{5-C&FCHNCHz(2-C&Cl)}(PPhs)l (40. Yield: X-ray Structure Analysis. Data Collection. Prismatic 45.0 mg (65%). Mp: 177 "C dec. Anal. Calcd for C33H28crystals (0.1 x 0.1 x 0.2 mm) were selected and mounted on ClFNPR: C, 55.12; H, 3.92; N, 1.95. Found: C, 54.90; H, 3.89; an Philips PW-1100 difiactometer (4a) or an Enraf-Nonius N, 1.91. lH NMR (acetone-de): 6 1.02 [dd, WHPt) = 84, CAD4 difiactometer (4c). Unit cell parameters were deter3J(HP)= 9, V(HF) = 7, Me] 4.29 [s, WHPt) = 11,CHz1, 8.55 mined from automatic centering of 25 reflections (8" 5 0 5 [s, 3J(HPt)= 55, CHN], (7.19 [m], 7.39 [ml, 7.65 [ml, aromat12", 4a; 12" I0 5 21", 4c) and refined by the least-squares = 63, F51. ics}, 19FNMR (acetone-de): 6 -98.29 [m, 3J(F6R) method. Intensities were collected with graphite-monochro31P NMR (acetone): 6 28.09 [s, 'J(PPt) = 24791. matized Mo Ka radiation, using the wI28 scan technique. For [PtMe(2,4,6-C&FsCHNCI&C&d(PPhs)21 (5b). Yield: 4a, 5271 reflections were measured in the range 2" IB 5 30"; 80 mg (85%). Mp: 110-115 "C dec. Anal. Calcd for 5140 were independent reflections, and 5089 were assumed C ~ ~ H ~ Z F ~ C, N 62.32; P ~ P ~H,: 4.31; N, 1.42. Found: C, 61.80; as observed by applying the condition Z 2 2dI). For 4c, 5677 H, 4.20; N, 1.38. lH NMR (acetone-&): 6 0.23 [dd, %J(HPt) = reflections were measured in the range 2" 5 0 5 30", 3925 of 63, 3 J ( H P ~=) 8, 3 J ( H P ~=) 6, Me] (4.84 (d), 5.02 (d), 'J(HH) which were assumed as observed by applying the condition Z = 14, CH2, AB pattern}, 9.00 [s, CHNI, 6.34 [m, CeHF31 (7.06 2 2.5dn. Three reflections were measured every 2 h as [m], 7.24 [ml, 7.36 [ml, aromatics}. 19FNMR (acetone-&): 6 orientation and intensity controls; significant intensity decay -120.17 [m, 3J(F5Pt) = 464, F5], -121.28 [m, 5J(F2F5) = 18, was not observed. Lorentz-polarization and absorption cor4J(F2F4)= 11,3J(F2H3)= 7, no Pt satellites, F21, -137.53 [m, rections were made. Further details are given in Table 6. 4J(F4Pt)= 114, 3J(F4F5)= 34, 4J(F4F2)= 3J(F4H3)= 10, Structure Solution and Refinement. The structures 6J(F4Ha)= 4, F4]. 31PNMR (acetone): 6 25.69 [m, 'J(pAPt) = were solved by Patterson synthesis, using the SHELXS 2379, PA],25.39 [d, 'J(PBR)= 1972, 'J(PAPB)= 16, PBI. I g 5 P t computer program,31 and refined by the full-matrix leastNMR (acetone): 6 -4633.02 [m, 'J(Pt-PA) = 24.30, 'J(Rsquares method, with the SHELX9332computer program. PB)= 1970, 3J(R-F5) = 444, 4J(Pt-F4) = 1111. The function minimized was Cw[lFo12- IFc1212, where w = [PtMe{3,5-C&F~CHNCH~(2-C~Cl)}(PPhs)zl (5d). (uz(Fo2) (0.1254P)2 + 2.178U9-l for 4a and w = (oz(Fo)+ Yield: 70 mg (75%). Mp: 147 "C dec. Anal. Calcd for C51H42ClFzNPzPt: C, 61.29; H, 4.23; N, 1.40. Found: C, 60.81; (31) Sheldrick, G. M. Acta Crystallogr. 1990,A46, 467. H, 4.27; N, 1.35. 'H NMR (acetone-&): 6 0.25 [dd, 2J(HR)= (32) Sheldrick, G. M. SHELX93: A computer program for crystal structure refinement; University of Gottingen, Germany, 1993. 64, 3 J ( H P ~=) 8, 3 J ( H P ~=) 7, Me] (4.81 (d), 4.95 (d), 2J(HH)
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Crespo et al.
364 Organometallics, Vol. 14, No. 1, 1995
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(0.253OPl2 17.055P)-1for 4c and P = (Fo2 2F2)/3. f, f ', and f " were taken from ref 33. All H atoms were computed and refined with an overall isotropic temperature factor, using a riding model. The final R factors, the number of refined parameters, and the maximum and minimum peaks in the final difference synthesis are given in Table 6.
work. We acknowledge financial support from the DGICYT (Ministerio de Educaci6n y Ciencia, Spain, project PB 93-0804)and a loan of K2PtC14 from Johnson Matthey Inc.
Acknowledgment. We thank Drs. J. Albert and J. Granell for kindly providing a manuscript of their recent
SupplementaryMaterial Available: Tables of hydrogen coordinates, anisotropic thermal parameters, least-squares planes and atomic deviations, and all bond lengths and angles (12 pages). Ordering information is given on any current masthead page.
(33) International Tables of X-Ray Crystallography; Kynoch Press: Birmingham, U.K., 1974;Vol. IV,pp 89-100, 149.
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