Organometallics 1995,14, 619-625
619
Synthetic, Structural, and Theoretical Studies on a Novel Rhodium(1) Complex Containing a z-Allyl-Type Wide Ligand Helmut Werner,*?+Norbert Mahr,? Gernot Frenking,*$fand Volker Jonasf Institut fur Anorganische Chemie der Universitat Wiirzburg, Am Hubland, 0-97074 Wiirzburg, Germany, and Fachbereich Chemie der Philipps- Universitat Marburg, Hans-Meerwein-Strasse, 0-35043 Marburg, Germany Received September 12, 1994@ Whereas the reaction of [RhCl(P-i-Prs)z], (1)with [CP~(M~)OHI(COZE~)CNZ and PhCHN2 gives the diazoalkane and dinitrogen complexes trans-[RhCl(NzC(COzEt)(CPh(Me)OH)}(Pi-Pr&I(Z) and trans-[RhCl(Nz)(P-i-Pr3)~] (3),respectively, the mononuclear yliderhodium(1) compound [RhCl(P-i-Pr&-Pr3P=CHC(O)Ph)l (4) is obtained on treatment of 1 with PhC(-0)CHNz. It reacts with CO or CN-t-Bu to generate the formerly unknown acyl ylide i-Pr3PCHC(0)Ph (5). The X-ray structure analysis of 4 (monoclinic, space group P21/c (No. 14), with a = 11.280(3) A, b = 15.201(2) A, c = 17.041(5) A, ,6 = 92.36(1)”, and 2 = 4) reveals the presence of a y3-allyl-type unit which is coordinated via oxygen and two carbon atoms to the metal center. The nature of the bonding between the modified acyl ylide ligand H3PCHC(=O)CH3 and rhodium(1) has been investigated by ab initio methods at the MP2 level. The is very calculated structure of the hypothetical molecule [RhCl(PH3){H3PCHC(O)CH3}1(4‘) similar to the geometry of 4 obtained by X-ray analysis. In contrast to 1, the alkynylrhodium(I) compounds trans-[Rh(C~CR)(CzH4)(P-i-P13)~1(6,7) react with PhC(-O)CHNz to give the (11,15). The preparation diazoalkane complexes trans-[Rh(C3CR)(N~C(H)(COPh)}(P-i-pr3)~1 10,12-14) will of other derivatives of composition trans-[Rh(C~CR)(NzCR’R”)(P-i-Pr3)21(8also be described.
Introduction During attempts to extend the series of rhodiumcarbon double bond systems trans-[RhCl(=C=CRR’)~ll and trans-[RhCl(=C=C=CRR’)Lz12 t o include the corresponding carbene rhodium complexes trans-[RhCl(=CRR)Lz] (L = P-i-Pr3, PR-i-Pr2, PMe-t-Buz etc.), we recently found3 that with [RhCl(P-i-Prs)zl, (1)as starting material neither CHzNz nor CPhzNz forms the expected product containing a Rh-CRz bond. Instead, with CH2Nz the ethene derivative trans-[RhCl(CZH& (P-i-Pr&I and with CPhzNz the diphenyldiazomethane rhodium complex trans-[RhCl(NzCPh2)(P-i-Pr3)21 were obtained. Whereas the latter is stable at room temperature under argon, it smoothly reacts with ethene and, surprisingly, to give trans-[RhCl(C2H4)(P-i-Pr&] 1.1-diphenylpropene. This olefin, which formally is built up by the linking of the :CPhz fragment of the diazoalkane with the ethene isomer :CHCH3, can be prepared catalytically from CzH4 and CPh2N2 in the presence of various mono- or dimeric rhodium(1)c ~ m p l e x e s . With ~$~ [RhCl(CzH4)~1zas the catalyst, turnover numbers of Universitat Wurzburg. Universitat Marburg. Abstract published in Advance ACS Abstracts, December 1, 1994. (1)(a)Garcia Alonso, F. J.;Hdhn, A,; Wolf, J.; Otto, H.; Werner, H. Angew. Chem. 1985,97,401-402.Angew. Chem. Int. Ed. Engl. 1985, 24,406-407. (b) Werner, H.; Garcia Alonso, F. J.; Otto, H.; Wolf, J. 2. Naturforsch., B: Anorg. Chem., Org. Chem. 1988,43,722-726.(c) Brekau, U. 2. Naturforsch., B: Anorg. Chem., Org. Chem. Werner, H.; 1989,44,1438-1446. (d) Rappert, T.;Nurnberg, 0.;Mahr, N.; Wolf, J.; Werner, H. Organometallics 1992,11, 4156-4164. (2) (a) Werner, H.; Rappert, T. Chem. Ber. 1993,126,669-678.(b) Werner, H.; Rappert, T.; Wiedemann, R.; Wolf, J.; Mahr, N. Orgunometallics 1994,13,2721-2727. (3)Wolf, J.; Brandt, L.; Fries, A.; Werner, H. Angew. Chem. 1990, 102,584-586. Angew. Chem. Int. Ed. Engl. 1990,29,510-512. +
*
@
about 500 have been a ~ h i e v e d . Although ~ for other substrates, which may contain a functional group in either the starting olefin or the diazo derivative, the turnover numbers are much less (usually 5-30), the important point is that in most of these catalytic processes a high degree of regio- and stereoselectivity is ~bserved.~a~ In order to gain more insight into the mechanism of the novel C-C coupling reaction, we decided inter alia to prepare rhodium(1) compounds with other diazoalkanes than CPhzNz and to vary the anionic ligand Xwhich in most of the previous work was chloride. In the course of these studies we discovered the formation of a new phosphorus ylide which is generated in the coordination sphere of the metal but can easily be displaced by CO. The n-allyl type bonding of the ylide, for which there is no precedence, has been confirmed by X-ray crystallography and investigated in detail by ab initio calculations. This work will also be described.
Results and Discussion Reactions of Functionalized Diazoalkanes with [RhCl(P-i-Prs)~l.In analogy to CPhzNz and other diaryldiazomethane derivative^,^,^ the chiral compound [CPh(Me)OH](COzEt)CNzreacts with 1 to give a diazoalkane rhodium complex instead of a carbene rhodium compound (Scheme 1). Compound 2 which has (4)Short reviews: (a) Werner, H. Ninth Synthetic Organic Chemistry Symposium (SOCS-9), Kyoto, 1992,Abstr. pp 29-33. (b) Werner, H. J. Organomet. Chem. 1994,475,45-55. (5) Mahr, N. Dissertation, Universitat Wurzburg, 1994. (6)(a) Brandt, L. Dissertation, Universitat Wurzburg, 1991. (b) Fries, A. Dissertation, Universitat Wiirzburg, 1993.
0276-7333/95/2314-0619$09.00/00 1995 American Chemical Society
620 Organometallics, Vol. 14, No. 2, 1995
Werner et al.
Scheme 1 +
[CPh( Me) OH]( E)CN,
.L
E ,
7CI,TRh-NzC,-,Ph C c, I Me 2 OH
C r
4
6
( C = PiPr,; E = C02Et)
been isolated as a red air-sensitive solid is both thermally stable and chemically rather inert. In presence of ethylene it does not undergo a ligand exchange like truns-[RhCl(NzCPh2)(P-i-Pr3)21 and on heating it does not eliminate a carbene fragment. The "end-on" coordination of the diazoalkane ligand in 2 is indicated by the N-N stretching frequency in the IR spectrum (1955 cm-l) which appears in the same region as for similar square-planar diazoalkane r h ~ d i u mand ~ , ~iridium compounds.' The position of the v(C=O) band in the spectrum of 2 and in that of the free ligand is almost identical and thus an additional interaction between the carbonyl group and the metal center can be excluded. Surprisingly, on treatment of 1 with the diazoacetic ester (C02Et)CHNzthe dinitrogen complex 3 is formed instead of a diazoalkane rhodium compound related t o 2. This compound has originally been prepared by Busetto and co-workers from [RhCl(C8H&Iz and P-iPr3 in the presence of N2* and has been crystallographically characterized by Ibers at ale9Compound 3 is also obtained from 1 and CH3CHN2, PhCHNz or other highly reactive diazoalkanes which cannot be used together with ethene as substrates in the new olefin synthesis. An unexpected product is formed in the reaction of 1 with 1-diazo-2-phenylethanone. If the two starting materials are combined in ether solution at room temperature, a spontaneous gas evolution (Nz) occurs and after a short time a red solid precipitates. With the exception of pentane, hexane, and ether, this new compound 4 (Scheme 1) is easily soluble in most common organic solvents but is not exceedingly stable in solution. The rhodium-mediated formation of an acyl ylide ligand of composition i-PrsPCHC(=O)Ph is indicated by a signal for the CH proton at 6 2.19 in the lH NMR, by a doublet-of-doublets for the CH carbon at 6 9.04 in the 13CNMR, and by the appearance of another doublet-of-doubletsat 6 39.14 in the 31P-NMRspectrum having a Rh-P coupling constant of 7.4 Hz. This value is much smaller than that of the second 31P signal at 6 (7)Brandt, L.;Wolf, J.;Werner, H. J . Organomet. Chem. 1993,444, 235-244. ( 8 ) Busetto, C.; D'Alfonso, A,; Maspero, F.; Perego, G.; Zazzetta, A. J . Chem. SOC.,Dalton Trans. 1977,1828-1834. (9)Thorn, D. L.;Tulip, T. H.; Ibers, J. A. J . Chem. Soc., Dalton Trans. 1979,2022-2025.
L
20
Figure 1. Molecular structure of 4.
67.60 [J(RhP) = 214 Hzl which belongs to the phosphorus atom of the P-i-Pr3 ligand. Characteristic features, which support the assumption that the ylide is coordinated via carbon and oxygen to the metal, are the 13C NMR resonance of the carbonyl carbon atom at 6 191.68 that is shifted to higher field compared with an uncoordinated PhC-0 group and the position of the v(C=O) band in the IR spectrum which appears at significantly lower wave numbers (1572 cm-l) than for intact acetophenone derivatives.1° We note that a similar lowfrequency shift of the C=O stretch has been observed for rhodiumll and iridium complexes12 in which a substituted vinyl ligand such as CH=CH-C(R)=O or CH=CMe-C(R)=O (R = Me, OMe) is linked via the a-carbon and the carbonyl oxygen atom to the metal. Molecular Structure of 4. Since on the basis of the spectroscopic data the exact arrangement of the ylide ligand to the Rh(PR3)X fragment could not be established unambigously, a single-crystal X-ray analysis of compound 4 was carried out. The SCHAKAL drawing (Figure 1) reveals that the four atoms C1, P2, 0, and C1 form a distorted square around the metal with the carbon atom C2 above the respective plane. The bond length Rh-C1[2.101(4) AI is comparable to that in other ylide-rhodium complexes,13and this is equally true for the Rh-C1-P1 bond angle (Table 1). The P-C1 distance [1.799(4)AI is shorter than would be expected for a phosphorus-carbon single bond but is in good agreement with data for related metal ~ 1 i d e s . l ~ The most interesting aspect of the structure, however, is the coordination of the acyl group which together with (10)Hesse, M.; Meier, H.; Zeeh, B. Spektroskopische Methoden in der organischen Chemie, 3rd ed.; Verlag Thieme: Stuttgart-New York, 1987;Chapter 2. (11)Dirnberger, T.;Werner, H. Chem. Ber. 1992,125,2007-2014. (12)(a)Werner, H.; Dirnberger, T.; Schulz, M. Angew. Chem. 1988, 100, 993-994. Angew. Chem. Int. Ed. Engl. 1988,27,948-950. (b) Dirnberger, T.Dissertation, Universitat Wiirzburg, 1991. (c) Papenfuhs, B. Diplomarbeit, Universitat Wurzburg, 1990. (13)(a) Werner, H.: Hofmann, L.: Paul. W.: Schubert. U. Organometallics 1988,7,1106-1111. (b) Werner, H.; Schippel, 0.;WGf, J.; Schulz, M. J . Organomet. Chem. 1991,417,149-162.
Novel RhI Complex Containing a mAllyl-Type nide
Organometallics, Vol. 14,No. 2, 1995 621
Table 1. Selected Experimental Bond Distances and Angles with ESD's for 4a Rh-c1 Rh-P2 Rh-0 Rh-C1 Rh-C2 P1-c1 Pl-C9 P1-c12 Cl-Rh-P2 C1-Rh-0 c1-Rh-c1 Cl-Rh-C2 P2-Rh-0 P2-Rh-Cl P2-Rh-C2 0-Rh-C1 0-Rh-C2 Cl-Rh-C2
Bond Distances (A) 2.369 (1); (2.311) P1-C15 2.213 (1); (2.182) P2-Cl8 2.177 (3); (2.126) P2-C21 2.101 (4); (2.032) P2-C24 2.041 (4); (1.983) 0-C2 1.799 (4); (1.763) Cl-C2 1.821 (4) C1-H 1.830 (4) C2-C3
1.839 (4) 1.859 (5) 1.866 ( 5 ) 1.870 (5) 1.305 (5); (1.333) 1.438 (6); (1.487) 1.07 (4); (1.092) 1.489 (6); (1.502)
Bond Angles (deg) 93.1 1 (4); (89.3) Rh-O-C2 101.19 (8); (104.6) Rh-C1-P1 163.6 (1); (166.6) Rh-Cl-C2 131.6 (1); (136.9) Pl-Cl-C2 158.57 (9); (162.4) Rh-C2-0 102.6 (1); (99.2) Rh-C2-C1 123.7 (1); (125.1) Rh-C2-C3 65.2 (1); (69.4) O-C2-C1 35.9 (1); (37.6) O-C2-C3 40.6 (2); (43.5) Cl-C2-C3
66.4 (2); (65.3) 117.9 (2); (101.4) 67.5 (2); (66.5) 116.7 (3); (1 15.2) 77.8 (2); (77.0) 72.0 (2); (70.0) 124.0 (3); (131.7) 114.4 (4); (114.1) 120.0 (4); (121.4) 125.2 (4); (123.3)
Figure 2. Optimized geometry of 4'.
[Rh(y3-CH2CsH4-4-CH3)(P-i-Pr3)21 [2.343(3)and 2.253(3) or [C5H5Rh(=C=CHPh)(P-i-Pr3)1 [2.263(6)
and the small dihedral angle [14.9(13)"1 between the [Cl, C2, 01 plane and the plane of the phenyl group. This indicates a substantial degree of n-n interaction the carbon atom C 1 forms a y3-allyl-typeunit. Evidence between the six-membered ring and the y3-allyl-type for this is provided by (i) the almost perpendicular ligand. arrangement of thelC1, Rh, P21 and the [Cl, C2, 01 Theoretical Studies. In order to investigate the planes [dihedral angle 91.2(9)"1, (ii)the Cl-C2-0 angle bonding situation between the rhodium atom and the of 114.4(4>0which is significantly shorter than for a free y3-allyl-type unit of 4, we optimized the geometry of the sp2 ylide carbon center,14 but quite similar t o that in 4' at the MP2 level using quantum mechanical complex y3-allylor y3-benzylrhodium compounds,15and (iii)the ab initio methods. The P-i-Pr3 groups of 4 are replaced shortening of the Cl-C2 and the lengthening of the 4 by PH3 groups and the phenyl substituent is in C2-0 distances if compared with those of corresponding replaced by a methyl group. Details of the theoretical It should be mentioned yl-bonded ylide ~omp1exes.l~ calculations are given in the method section. Previous that an analogous elongation of the C-0 bond has been studies have shown that the geometries of low-valent found in several aldehyde and ketone transition-metal transition metal complexes are predicted at this level compounds in which the carbonyl moiety is linked via of theory in good agreement with experiment.20 carbon and oxygen to the metal center,16as well as in The optimized geometry of 4' is shown in Figure 2. oxoallyl-type metal c0mp1exes.l~We also note that Alt The calculated structure of the y3-allylrhodium unit of et a1.18 have prepared cyclopentadienyl molybdenum 4' is very similar to the geometry of 4 obtained by X-ray and tungsten compounds of composition [ C ~ H ~ M { K ~ structure analysis (Figure 1). The optimized geometry (O,C)-OC(CH3)=CHCHPMe3}(C0)21 (M = Mo, W) in of 4 has a bicyclic central moiety with a calculated which the acyl ylide unit is generated from an acylvinyl folding angle of 122"between the Rh-Cl-C2 plane and ligand and PMe3 and where a similar bonding situation the Rh-C2-0 plane. The X-ray structure analysis of as in 4 exists. Other relevant structural data for 4 are 4 gives a folding angle of 121.0(3)" between the Rhthe Rh-0 bond length of 2.177(3) A which is almost C1-C2 and the Rh-C2-0 planes. The theoretically the identical to that in [Rh(y2-02CCH~)(P-i-Pr3)21,15a predicted bond lengths of 4' are in good agreement with Rh-P2 distance of 2.213(1)A which is shorter than in the experimental values of 4 (Table 11, if the different substituents of the two complexes are taken into ac(14)Inter alia: (a) Facchin, G.; Bertani, R.; Calligaris, M.; Nardin, G.; Mari, M. J . Chem. SOC.,Dalton Trans. 1987, 1381-1387. (b) count. The theoretical bond lengths between Rh and Facchin, G.;Bertani, R.; Zanotto, L.; Calligaris, M.; Nardin, G. J. the y3-allyl-type unit are slightly shorter (Rh-C1 = Organomet. Chem. 1989,366,409-420. ( c ) Vicente, J.; Chicote, M. T.; Fernandez-Baeza, J.;Martin, J.;Saura-Clamas, I.; Turpin, J.;Jones, 2.032 A; Rh-C2 = 1.983 A; Rh-0 = 2.126 A) than the R. G. J . Organomet. Chem. 1987,331,409-421. observed interatomic distances (Rh-Cl= 2.101 A; Rh(15)(a) Werner, H.; Schafer, M.; Numberg, 0.;Wolf, J. Chem. Ber. C2 = 2.041 A; Rh-0 = 2.177 A). 1994,127,27-38. (b) Chappel, S.D.; Cole-Hamilton, D. J.; Galas, A. M. R.; Hursthouse, M. B.; Walker, N. P. C. Polyhedron 1986,4,121The nature of the bonding of the y3-allylrhodiumunit 125. ( c ) Burch, R.R.; Muetterties, E. L.; Day, V. W. Organometallics is revealed by the topological analysis of the electron 1982,1,188-197. (16)(a) Martin, B.D.; Matchett, S. A.; Norton, J. R.; Anderson, 0. density distribution and the associated gradients and P. J . Am. Chem. Soc. 1986.107.7952-7959.(b) Huann. Y.H.: Gladvsz. Laplacian.21 Figure 3 shows the contour line diagrams J. A. J . Chem. Educ. 1988,65,'298-303.(c) Klein, KP.;Mendeg N: of the Laplacian of 4 in the Rh-Cl-C2 plane (Figure Q.; Seyler, J. W.; Arif, A. M.; Gladysz, J. A. J . Organomet. Chem. 1993, 450,157-164. (d) Mendez, N.Q.; Arif, A . M.; Gladysz, J. A. Angew. 3a) and in the Rh-C2-0 plane (Figure 3b). The Chem. 1990,102,1507-1509.Angew. Chem. Int. Ed. Engl. 1990,29, electronic structure of the Rh-C1-C2 unit is character1473-1475. (e) Mendez, N. Q.; Mayne, C. L.;Gladysz, J. A.Angew. ized by three bond paths and three bond critical points Chem. 1990,102,1509-1511.Angew. Chem. Int. Ed. Engl. 1990,29, 1475-1477. between the three atoms and one ring critical point. a
Calculated values for 4' are given in parentheses.
(17)(a) Guggolz, E.; Ziegler, M. L.;Biersack, H.; Herrmann, W. A. J . Organomet. Chem. 1980,194,317-324. (b) Hart, I. J.; Jeffery, J. C.; Lowry, R. M.; Stone, F. G. A.Angew. Chem. 1988,100,1769-1770. Angew. Chem. Int. Ed. Engl. 1988,27,1703-1704. (c) Dossett, S.J.; Pilotti, M. U.; Stone, F. G . A. Polyhedron 1990,9,2953-2958. (18)Alt, H. J.;Schwarzle, J. A.; Kreissl, F. R. J . Organomet. Chem. 1978,152, C57-C59.
(19)Werner, H.;Wolf, J.; Garcia Alonso, F. J.; Ziegler, M. L.; Serhadli, 0. J . Organomet. Chem. 1987,336,397-411. (20)(a) Ehlers, A. W.; Frenking, G. J . Am. Chem. SOC.1994,116, 1514-1520. (b)Ehlers, A.W.; Frenking, G. Organometallics, submitted.
622 Organometallics, Vol. 14,No. 2, 1995
Werner et al.
Thus, the topology of the electronic structure indicates the cyclic nature of the Rh-C1-C2 moiety, which should be considered as a rhodium-cyclopropane unit.21 The C 1 and C2 carbon atoms possess droplet-shaped areas of electron concentration (@&) < 0, solid lines) pointing toward the rhodium atom, which illustrates the electron donation toward the metal atom. The Laplacian distribution of the Rh-C2-0 unit (Figure 3b) shows a different type of structure. There are bond paths between Rh and C2 and between C2 and the oxygen atom, but there is no bond path between Rh and 0. This means that the Rh-C2-0 unit should not be considered as a cyclic structure. Although the interatomic distance between Rh and 0 is rather short 2.177 A in 4), the gradient field (Rh-0 = 2.126 A in 4, indicates that there is no bond between these atoms. The attractive Coulomb interactions between Rh and 0 in 4 are not sufficient to form a bond as defined by the topological analysis of the electronic structure.21 Generation of the Free Ylide. Since in contrast to ordinary x-allyl transition metal complexes the allyltype ligand in 4 is nonionic, it can easily be displaced from the coordination sphere by CO. If carbon monoxide is passed through a solution of 4 in toluene, a change of color from orange-red t o bright yellow occurs. After removal of the solvent and extraction of the residue with pentane, a mixture of products is obtained which consists of the free ylide 5 (Scheme 1)as well as equal quantities of [RhC1(CO)21222and truns-[RhCl(CO)(P-iPr3)~l.~ If tert-butyl isocyanide is used instead of CO, the ylide 5 is isolated as a light-yellow oil. Typical features of the lH-NMR spectrum of 5 are (i) the doublet of the i-Pr3PCH proton at 6 3.59 which is shifted by ca. 4 ppm to lower field compared with ~ - P ~ ~ P Cand HZ,~~ (ii) the large P-H coupling constant of this signal of 19.5Hz which reveals a considerable contribution of the zwitterionic resonance form i-Pr3P+-CH=l:(Ph)O-.24 The 13CNMR spectrum of 5 displays besides the signals Figure 3. Contour line diagrams of the Laplacian distribution Ve(r)for 4'. Dashed lines indicate charge depletion for the isopropylphosphine and phenyl carbons a reso(Vg(r)> 0), solid lines indicate charge concentration (Venance for the ylide carbon atom at 6 42.04, significantly (r) < 0). The solid lines connecting the atomic nuclei are deshielded compared with 4, and a characteristic douthe bond paths; the solid lines separating the atomic nuclei blet for the carbonyl carbon atom at 6 184.68. In the indicate the zero-flux surfaces in the plane. The crossing 31PNMR spectrum of 5 the signal is observed a t about points of the bond paths and zero-flux surfaces are the bond the same chemical shift as that of the unsubstituted critical points rt,. ylide ~ - P ~ ~ P C H Z . ~ ~ Reaction of the Alkynyl Complexes trans-[Rhnation of ethene to give the expected products (Scheme (C~CR)(C2H4)(P-i-Pr3)23.In view of the fact that in 2). Compounds 8-15 are deeply colored microcrystalline square-planar iridium complexes truns-[IrX(CzH4)(P-isolids which are only moderately air-sensitive and PI-&] the replacement of X = C1 for X = CH3 favors the considerably more stable in solution than their chlorocoordination of a N2CRR ligand,' we were interested rhodium counterparts trulzs-[RhCl(N2CRR)(P-i-Pr3)21. to find out whether a similar effect is also observed in The yield of 8-15 in the straightforward synthesis is 80rhodium chemistry. Since alkyl rhodium compounds 95%. The proposed structure with an end-on bonded such as truns-[RhCH3(C~H4)(P-i-Pr3)21 or truns-[RhCHzdiazoalkane ligand is supported in particular by the IR Ph(CzHd(P-i-Pr3)21are still unknown,25we decided t o spectra in which the v(N=N) stretch (-1920 cm-l) is use the alkynyl(ethene) complexes 6 and 7 as related shifted by ca. 100-150 cm-' to lower wavenumbers starting materials.26 They both react with PhzCN2, compared with the parent N2CRR molecules. The C12HsCN2, PhC(=O)CPhN2, and PhC(=O)CHN2 by elimichemical shift and the splitting pattern of the signals for the phosphines in the lH, 13C, and 31PNMR spectra (21) Bader, R. F. W. Atoms in Molecules. A Quantum Theory; Oxford are very similar to those of 6 and 7 and therefore we Univ. Press: Fair Lawn, NJ, 1990. assume that the stereochemistry of the starting materi(22) McCleverty, J. A,; Wilkinson, G. Inorg. Synth. 1968,8, 211214. als and the products is the same. It should be empha(23) Koster, R.; Simic, D.; Grassberger, M. A. Liebigs. Ann. Chem. sized that in contrast to 1 (see Scheme 1)compounds 6 1970,739, 211-219. (24) (a) Malisch, W.; Rankin, D.; Schmidbaur, H. Chem. Ber. 1971, 104,145-149. (b) Ostoja-Starzewski, K. A,; tom Dieck, H. Phosphorus 1976,6,177-189. (25) Schafer, M. Dissertation, Universitat Wurzburg, 1994.
(26)(a) Schafer, M.; Wolf, J.; Werner, H. J . Cheni. SOC.,Chem. Commun. 1991,1341-1343. (b) Schafer, M.; Wolf, J.; Werner, H. J . Organomet. Chem. 1994,in press.
Novel RhI Complex Containing a n-Allyl-Type n i d e
Scheme 2 R'R"CN
R - C E C- R-h'
L
Np C R ' R "
'L R - C 5 C -Rh-)('
8-16
L
L'
R=H
6
R
7
=
tBu
/L
(R = tBu)
tBu-CZC-Rh-NpCHPh L/
16
+
tBu-CEC;Rh-NEN.L
L
17 R R'
-
H
! tBu
R" = Ph
R'. R " = CjzH, R' = C ( 0 ) P h ; R" = P h R' = C ( 0 ) P h : R " = H
and 7 react with PhC(=O)CHN2 to give a stable diazoalkane complex and not an ylide rhodium(1) derivative. In contrast to compound 1,which reacts with PhCHN2 by decomposition of the diazoalkane, the alkynyl complex 7 on treatment with phenyldiazomethane affords two products. It is quite obvious from NMR measurements at variable temperatures that the expected diazoalkane rhodium complex 16 (see Scheme 2) is formed initially. However, it then is converted with a comparable reaction rate t o the dinitrogen derivative 17. Several attempts t o separate the two compounds by fractional crystallization or column chromatography failed. The IR spectrum of the product mixture displays a N-N stretching frequency for 16 at 1935 cm-l and for 17 at 2120 cm-l, the latter of which is quite similar t o that of tr~ns-[RhCl(N2)(P-i-Pr3)21.~,~ Concluding Remarks
The present investigations have shown that the reaction of 1 with substituted diazoalkanes can lead to products of different structural types. The most unusual of these products certainly is the acyl ylide complex 4 in which a v3-allyl-type unit is coordinated to the metal center. Although the X-ray structural data of 4 reveal a rather short interatomic distance between rhodium a n d oxygen, ab initio calculations indicate that there is no bond between these atoms. Despite this result, we nevertheless consider the novel acyl ylide i-PrsPCHC(=O)Ph as a 4-electron donor ligand which provides a 16-electron configuration for the rhodium(1) atom in compound 4. A similar bonding situation probably exists in some oxoallyl or aldehyde and ketone transition-metal complexes in which a M-0 interaction is also indicated by the structural data.16J7 Experimental Section All reactions were carried out under an atmosphere of argon by Schlenk tube techniques. The starting materials [RhCl(P-i-Pr&l, (1),27 truns-[Rh(C~CH)(C~H4)(P-i-Pr3)~1 (6),26 trans(27) Werner, H.; Wolf, J.;Hohn, A. J. Orgunomet. Chem. 1986,287, 395-407.
Organometallics,
Vol.14,No. 2, 1995 623
[ R ~ ( C ~ C - ~ - B U ) ( C ~ H ~ ) ((7),26 P - ~ -[CPh(Me)OHI(COzEt)P~~)~I CNz," PhC(=O)CHN2," P ~ z C N ~C, ~I ~' H ~ C NPhC(=O)Z,~~ P ~ C N Zand ,~P ~ ~ C H N were Z ~ ~prepared by published procedures. Other substrates were commercial products from Aldrich and Fluka. NMR spectra were recorded on JEOL FX 90 Q, Bruker AC 200, and Bruker AMX 400 instruments, and IR spectra on a Perkin-Elmer 1420 infrared spectrometer. Melting points were measured by DTA. Preparationof trans-[RhCl(N2C(CO&t)(CPh(Me)OH))(P-i-Pr3)21(2). A solution of 1 (76 mg, 0.166 mmol for n = 1) in 10 mL of ether was treated at -50 "C with a solution of [CPh(Me)OHI(COzEt)CN2(78 mg, 0.16 mmol) in 5 mL of ether and with continuous stirring slowly warmed up to room temperature. A color change from violet t o red occurred. The reaction mixture was concentrated to ca. 1mL in vacou and 5 mL of pentane was added. After the solution was stored at -78 "C, red crystals precipitated, which were filtered off, washed with pentane (-30 "C), and dried in vacuo: yield 92 mg (80%);mp 98 "C dec. Anal. Calcd for Cz&56NzC103PzRh: C, 51.99; H, 8.14; N, 4.04. Found: C, 52.05; H, 8.97; N, 3.88. IR (Kl3r): v(OH) 3400, v(N=N) 1955, v(C=O) 1615 cm-'. 'H NMR (C6D6, 200 MHz): 6 7.68 (d, 3J(HH) = 6.1 Hz, 2H, ortho-H of C a s ) , 7.25-7.04 (m, 3H, C a b ) , 5.20 (br, s, lH, OH), 4.01 (9, V(HH) = 7.1 Hz, 2H, CH2CH3), 2.39 (m, 6H, PCHCHs), 1.78 (s,3H, CCH3), 1.30 (dvt, J(HH) = 7.0, N = 13.5 Hz, 18H, PCHCH3), 1.27 (dvt, J(HH) = 7.0, N = 13.5 Hz, 18H, PCHCH3), 0.95 (t, 3J(HH)= 7.1 Hz, 3H, CHzCH3). I3C NMR (C6D6,50.3MHz): 6 162.47 (s,c=o),149.55 (S, ipso-c of c&,), 128.33, 127.06, 125.42 (all s, C6H5), 77.95 (br, s, CNZ),70.95 (s,C(CH3)0H),59.79 (s,O ~ Z C H 30.40 ~ ) , (s,C(C%&)oH),23.66 (vt, N = 18.3 Hz, PCHCH3), 19.95 (s, PCHCH3), 14.67 (s, OCHzCH3). 31PNMR (CfjD6, 81.0 MHz): 6 42.39 (d, 'J(RhP) = 117.7 Hz). Reaction of 1 with (C02Et)CHN2. A solution of 1 (61 mg, 0.13 mmol) in 5 mL of pentane was treated as described for 2 with a solution of (C0zEt)CHNz (15mg, 0.13 mmol) in 2 mL of pentane. A light-brown solid was obtained which spectroscopi(3).[2a1 cally was identified as trans-[RhCl(Nz)(P-i-Pr3)~1 Preparationof [RhCl(P-i-Prs)(i-Pr3P=CHC(O)Ph)l (4). A solution of 1 (90 mg, 0.22 mmol) in 5 mL of ether was treated with a solution of PhC(=O)CHNZ (32 mg, 0.22 mmol) in 2 mL of ether. A spontaneous color change from violet to red-brown occurred and a gas evolution took place. After the solution had been stirred for 1 min at room temperature, an orangered air-sensitive solid precipitated which was separated from the mother liquor at -30 "C, washed with 5 mL of pentane (-30 "C), and dried in vacuo: yield 97 mg (77%); mp 90 "C dec. Anal. Calcd for C26H4&10P&h: C, 54.13; H, 8.38. Found: C, 54.41; H, 8.41. MS (70 eV): mlz = 278 (0.35) (iPr3P=CHC(O)C&+), 201 (0.13) (i-Pr3P=CHCOf), 105 (0.90) (C&,CO+). IR (KBr): v(C=O) 1520, v(P=C) 885 cm-'. IH NMR (C&, 400 MHz): 6 8.41 (d, 3J(HH) = 7.3 Hz, 2H, ortho-H of C&5), 7.36-7.04 (m, 3H, C a s ) , 2.47 (m, 3H, RhPCHCH3), 2.17 (m, 3H, C=PCHCH3), 2.19 (d, 2J(PH)= 14.7 Hz, lH, P=CH), 1.26 (dd, 3J(HH) = 7.4, V(PH) = 14.8 Hz, 9H, RhPCHCH3), 1.21 (dd, 3J(HH)= 7.4, 3J(PH) = 13.2 Hz, 9H, RhPCHCHs), 1.12 (dd, 3J(HH) = 7.2, 3J(PH) = 13.1 Hz, 9H, C=PCHCH3), 1.07 (dd, 3J(HH)= 7.5, 3J(PH) = 15.5 Hz, 9H, C=PCHCH3). I3C NMR (C6D6, 50.3 MHz): 6 191.68 (d, 'J(RhC) = 45.8 Hz, C=O), 128.83, 128.30, 127.78, 126.49 (all S, C6H5), 26.38 (d, 'J(PC) = 21.6 Hz, C=PCHCH3), 22.83 (d, 'J(PC) = 43.4 Hz, RhPCHCH31, 20.33, 20.15 (both S, (28) Schollkopf, U.; Bbnhidai, B.; Frasnelli, H.; Meyer, R.; Beckhaus, H. Liebigs Ann. Chem. 1974,1767-1783. (29) Regitz, M.; Menz, F. Chem. Ber. 1968,101,2622-2632. (30) (a) Smith, L. I.; Howard, K. L. Organic Synthesis; Wiley: New York, 1955; Collect. Vol. 3, pp 351-352. (b) Miller, J. B. J . Org. Chem. 1969,24,560-561. (31) Baltzly, R.; Metha, N. B.; Russel, P. B.; Brooks, R. E.; Grivsky, E. M.; Steinberg, A. M. J . Org. Chem. 1961,26,3669-3676. (32) Nenitzescu, C. D.; Solomonica, E. Organic Synthesis; Wiley: New York, 1993; Collect. Vol. 2, pp 496-497. (33) Yates, P.; Shapiro, B. L. J. Org. Chem. 1968,23,759-760.
624 Organometallics, Vol.14,No. 2, 1995
Werner et al.
pentane was treated as described for 8 with a solution of PhCC=PCHCH3), 18.20, 18.02 (both d, 'J(PC) = 2.6 Hz, (O)PhCN2(34 mg, 0.15 mmol) in 2 mL ofpentane. Red crystals RhPCHCH3), 9.07 (dd, 'J(RhC) = 42.5, 'J(PC) = 22.2 Hz, were obtained; yield 92 mg (91%); mp 64 "C dec. Anal. Calcd P=C). 31PNMR (C&, 36.2 MHz): 6 67.60 (dd, 'J(RhP) = for C34H53NzOPzRh: C, 60.89; H, 7.96; N, 4.17. Found: C, 213.5,3J(PP) = 4.4 Hz, RhP), 39.14 (dd, ?J(RhP) = 7.4, WPP) 60.80; H, 8.02; N, 4.25. IR (hexane): v(=CH) 3262, v(C=C) = 4.4 Hz, C=P). 1940, v(N=N) 1915 cm-'. 'H NMR (CtjDs,200 MHz): 6 7.58Preparation of i-Prfl-.CHC(O)Ph (5). (a)A slow stream 6.89 (m, 10H, C&), 2.66 (m, 6H, PCHCH3), 2.48 (dt, V(RhH) of CO was passed for ca. 30 s through a solution of 4 (60 mg, = 2.4, 4J(PH)= 1.3Hz, lH, CICH), 1.26 (dvt, J(HH) = 7.1, N 0.10 mmol) in 7 mL of toluene at room temperature. After = 13.5 Hz, 18H, PCHCH3), 1.20 (dvt, J(HH) = 6.9, N = 13.0 the solution had been stirred for 20 min, the solvent was Hz, 18H, PCHCH3). I3C NMR (C6D6, 50.3 MHz): 6 155.03 (s, removed and the residue was extracted with 30 mL of hexane. The extract contained a mixture of trans-[RhCl(CO)(P-i-Pr3)~] C=O), 140.09, 139.56, 130.02, 129.36, 128.28, 125.02 (all s, C6H5), 99.80 (br, s, CNz), 99.67 (dt, %J(RhC) = 12.9, 3J(PC)= and 5. (b) A solution of 4 (121 mg, 0.21 mmol) in 10 mL of 3.0 Hz, CICH), 97.61 (dt, 'J(RhC) = 54.5, V(PC) = 15.5 Hz, toluene was treated with t-BuNC (25 pl, 0.21 mmol) a t room C W H ) , 24.07 (vt, N = 17.6 Hz, PCHCHB),19.95, 19.80 (both temperature. A gradual color change from red-orange t o S, PCHCH3). 31PNMR (CsD6, 81.0 MHz): 6 37.86 (d, 'J(RhP) orange-yellow occurred. After the solution was stirred for 20 = 126.4 Hz). min, it was worked up as described for a. Removal of the solvent from the extract gave a yellow oil: yield 39 mg (67%). Preparation of trans-[Rh(C~CH){N2C(H)(COPh)}(Pi-Prs)zl (11). A solution of 6 (52 mg, 0.11 mmol) in 8 mL of 'H NMR (C&, 200 MHz): 6 8.35 (d, 3J(HH)= 7.9, *J(HH)= pentane was treated as described for 8 with a solution of PhC1.8 Hz, 2H, ortho-H of C&5), 7.33-7.15 (m, 3H, C&), 3.59 (-0)CHCNz (16 mg, 0.11 mmol) in 2 mL of pentane. Red (d, V(PH) = 19.5 Hz, l H , P=CHC(O)Ph), 2.35 (m, 3H, crystals were obtained: yield 51 mg (78%); mp 118 "C dec. PCHCH3), 0.96 (dd, 3J(HH) = 7.3, V(PH) = 14.8 Hz, 18H, Anal. Calcd for Cz8&~NzOP~Rh:C, 56.56; H, 8.31; N, 4.71. PCHCH3). I3C NMR (C&, 50.3 MHz): 6 184.68 (d, 'J(PC) = Found: C, 56.63; H, 8.31; N, 4.40. IR (KBr): v(=CH) 3270, 4.2 Hz, C=O), 143.51 (d, 3J(PC) = 14.8 Hz, ipso-C of C6H5), v(C=C) 1938, v(N=N) 1910, v(C=O) 1600,1577 cm-'. lH NMR 128.80, 127.85, 127.38 (all s, C6H5), 42.04 (d, 'J(PC) = 98.9 (CsD6, 200 MHz): 6 7.91 (d, 3J(HH)= 7.2 Hz, 2H, ortho-H of Hz, P=CHC(O)Ph), 22.36 (d, 'J(PC) = 50.4 Hz, PCHCH3), C&), 7.24-7.11 (m, 3H, C a b ) , 2.64 (m, 6H, PCHCH3), 2.45 17.67 (d, 2J(PC) = 18.5 Hz, PCHCH3). 31PNMR ( C & , ,81.0 MHz): 6 38.92 (s). (dt, 3J(RhH) = 2.4, 4J(PH)= 1.4 Hz, l H , CECH), 1.53 (s, lH, Preparation of trans-[Rh(C~CH)(NaCPhz)(P-i-Prs)zl NzCH), 1.27 (dvt, J(HH) = 7.1, N = 13.5 Hz, 18H, PCHCH3), 1.18(dvt,J(HH)= 6.9, N = 13.5Hz, 18H, PCHCH3). I3C NMR (8). A solution of 6 (65 mg, 0.13 mmol) in 5 mL of pentane (C&, 50.3 MHz): 6 152.57 (5, c=o),136.32, 129.48, 128.29, was treated under stirring a t -30 "C with a solution of Phz126.67 (all s, C6H5), 98.76 (dt, V(RhC) = 12.9, V(PC) = 3.6 CN2 (34 mg, 0.13 mmol) in 2 mL of pentane. While the Hz, CsCH), 81.13 (br, s, CNZ),24.06 (vt, N = 18.5 Hz, reaction mixture was warmed up to room temperature, a color PCHCH3), 19.93, 19.78 (both s, PCHCHs), signal of CGCH change from red to green occurred and a green solid precipiobscured by signals of C6D6. 31PNMR (CsDs, 81.0 MHz): 6 tated. After the solution had been further stirred for 10 min, 37.74 (d, lJ(RhP) = 124.8 Hz). the solvent was removed in vacuo. The residue was dissolved Preparation of trans-[Rh(C~Ct-Bu)(N2CPh2)(P-i-Prs),l in 10 mL of pentane and the solution was stored a t -78 "C. (12). A solution of 7 (102 mg, 0.19 mmol) in 5 mL of pentane Green crystals precipitated which were filtered off, washed was treated as described for 8 with a solution of PhzCN2 (37 with pentane (-30 "C), and dried in vacuo: yield 70 mg (80%); mp 35 "C dec. Anal. Calcd for C33H53N~PzRh:C, 61.68; H, mg, 0.19 mmol) in 2 mL of pentane. Green crystals were obtained; yield 127 mg (95%); mp 94 "C dec. Anal. Calcd 8.31; N, 4.36. Found: C, 61.42; H, 8.30; N, 4.01. MS (70 eV): C37H&&Rh: C, 63.60; H, 8.80; N, 4.04. Found: C, 63.37; mlz 642 (0.05) (M+), 448 (0.52) (M+ - P ~ ~ C N Z166 ) , (0.23) H, 8.96; N, 3.64. IR (hexane): v(C=C) 2070, v(N=N) 1930 (CPh2+). IR (hexane): v(=CH) 3280, v(C=C) 1935, v(N=N) 1920 cm-'. 'H NMR ( C & , ,200 MHz): 6 7.42-6.90 (m, 10H, cm-'. 'H NMR (C6D6, 200 MHz): 6 7.44-6.81 (m, 10H, ca5), 2.42 (m, 6H, PCHCH3), 1.28 (dvt, J(HH) = 6.9, N = 15.2 Hz, C a b ) , 3.02 (d, V(RhH) = 2.0 Hz, lH, C=CH, 4J(PH) not resolved), 2.43 (m, 6H, PCHCH3), 1.29 (dvt, J(HH) = 7.1, N = 36H, PCHCH3), 1.26 (5, 9H, C(cH3)3). I3C NMR (C&, 50.3 MHz): 6 136.81 (dt, 2J(RhC)= 14.4, V(PC) = 3.2 Hz, C=CR), 13.3 Hz, 36H, PCHCH3). I3C NMR (CsD6, 50.3 MHz): 6 130.25, 128.98, 124.71, 124.03 (all s, C6H5), 98.46 (dt, lJ(RhC) 129.90,129.04, 124.89,124.41 (all s, C a s ) , 113.83 (dt, 2J(RhC) = 51.3, 'J(PC) = 20.8 Hz, CzCR), 75.24 (br, s, C N 2 ) , 32.57 (s, = 15.3, 3J(PC) = 3.2 Hz, CICH), 109.18 (dt, 'J(RhC) = 51.3, CCH3), 29.80 (s, CCH3), 24.70 (vt, N = 18.5 Hz, PCHCH3), WPC) = 20.8 Hz, C W H ) , 75.46 (br, s, CNd, 24.86 (vt, N = 18.5 Hz, PCHCHa), 20.45 (9, PCHCH3). 31PNMR (C& 81.0 20.41 (s,PCHCH3). 31PNMR (C6D6, 81.0 MHz): 6 46.92 (d, WRhP) = 132.2 Hz). MHz): 6 46.42 (d, 'J(RhP) = 132.2 Hz). Preparation of trans-[Rh(C~H){N2C(ClzHs)}(P-i-Prs)d Preparation of truns-[Rh(C~Ct-Bu)(NzC(ClaHe))(P-i(9). A solution of 6 (86 mg, 0.18 mmol) in 8 mL of pentane Pr&1 (13). A solution of 7 (97 mg, 0.18 mmol) in 8 mL of was treated as described for 8 with a solution of ( C ~ Z H ~ ) C N Z pentane was treated as described for 8 with a solution of (35 mg, 0.18 mmol) in 4 mL of pentane. After the solvent was (C&~)CNZ(35 mg, 0.18 "01) in 2 mL of pentane. Green removed in vacuo, the residue was dissolved in 5 mL of acetone crystals were obtained: yield 104 mg (82%); mp 109 "C dec. Anal. Calcd for C37H59NzPzRh: C, 63.78; H, 8.89; N, 4.02. and the solution was stored a t -78 "C. Olive-green crystals precipitated which were filtered off and dried in vacuo: yield Found: C, 63.92; H, 8.80; N, 3.97. MS (70 eV): mlz 696 (0.04) ~ : IR (CsHs): v(CGC) 2050, Y(N=N) 1930 cm-'. 'H NMR (M'). 91 mg (79%); mp 89 "C dec. Anal. Calcd for C ~ ~ H ~ I N Z P ~ R C, 61.87; H, 8.03; N, 4.37. Found: C, 61.74; H, 8.23; N, 3.91. (C6D6, 200 MHz): 6 7.88-7.10 (m, 8H, c12ff8),2.42 (m, 6H, IR (KBr): v(=CH) 3240, v(C=C) 1935, v(N=N) 1920 cm-l. 'H PCHCH3), 1.25 (dvt, J(HH) = 7.1, N = 13.5 Hz, 36H, NMR (C&, 200 MHz): 6 = 7.86-7.10 (m, 8H, C&8), 3.12 PCHCHd, 1.22 (s,9H, C(CH3)3). I3C NMR (C&, 50.3 MHz): (dt, WRhH) = 2.0, 4J(PH)= 1.8 Hz, lH, CzCH), 2.41 (m, 6H, 6 139.89 (dt, V(RhC) = 13.9, 3J(PC) = 3.2 Hz, C=CR), 130.31, PCHCH3), 1.25 (dvt, J(HH) = 7.1, N = 13.5 Hz, 36H, 129.35, 125.52, 122.23, 120.95, 118.51 (all s, ClzHs), 97.99 (dt, PCHCH3). I3C NMR (C&, 50.3 MHz): 6 131.54, 130.46, WRhC) = 51.8, V(PC) = 21.3 Hz, CsCR), 74.42 (br, s, CN2), 125.70,122.65, 121.05,118.55 (all s, C12H8), 116.26 (dt, V(RhC) 32.38 (s, CCHs), 29.73 (s, CCH3), 24.77 (vt, N = 19.4 Hz, = 14.3, 3J(PC)= 3.7 Hz, CzCH), 71.20 (br, s, CNz), 24.92 (vt, PCHCH3), 20.25 (s,PCHCH3). 31PNMR (CsDs, 81.0 MHz): 6 N = 18.5 Hz, PCHCH3), 20.31 (s, PCHCH3), signal of C=CH 48.15 (d, 'J(RhP) = 129.3 Hz). obscured by signals of C&. 31PNMR (C&, 81.0 MHz): 6 Preparation of trans-[Rh(C=C-t-Bu){NaC(Ph)(COPh)}48.08 (d, 'J(RhP) = 129.3 Hz). (P-i-Pr&] (14). A solution of 7 (100 mg, 0.19 mmol) in 5 mL Preparation of ~~~~~-[R~(CECH){N~C(P~)(COP~)}(Pof pentane was treated as described for 8 with a solution of PhC(0)PhCN2(42 mg, 0.19 mmol) in 2 mL of pentane. Red i-Prd21 (10). A solution of 6 (73 mg, 0.15 mmol) in 8 mL of
Novel Rhl Complex Containing a z-Allyl-Type Ylide
Organometallics, Vol. 14,No. 2, 1995 625
diffractometer, Mo & radiation (0.709 30 A), graphite monocrystals were obtained: yield 120 mg (87%); mp 86 "C dec. chromator, zirkon filter (factor 16.4); T = 223 K o/29-scan, Anal. Calcd for C38H6lN20P2Rh: C, 62.80; H, 8.46; N, 3.85. max 29 = 46"; 4243 independent reflections measured, 2618 Found: C, 63.69; H, 8.73; N, 3.42. IR (KBr): v(CEC) 2080, regarded as beeing observed [F, > 3dF0)1.Intensity data were v(N=N) 1930, v(C+bbO) 1610 cm-l. 'H NMR (CsD6, 200 corrected for Lorentz and polarization effects, and an empirical MHz): 6 7.63-6.87 (m, 10H, C a s ) , 2.67 (m, 6H, PCHCHd, absorption correction ( p s c a n method) was applied. The 1.39 (s, 9H, C(CH3)3), 1.25 (dvt, J(HH) = 7.1, N = 13.5 Hz, minimum transmission was 97.56%. The structure was solved 18H, PCHCHs), 1.20 (dvt, J(HH) = 6.9, N = 12.8 Hz, 18H, by direct methods (SHELXS-86). Atomic coordinates and PCHCH3). l3cNMR (C6D6, 50.3 MHz): 6 154.42 ( 5 , c=o), anisotropic thermal parameters of the non-hydrogen atoms 140.22, 139.55, 129.94, 129.32, 128.27, 127.50 (all s, C&), were refined by full-matrix least squares (329 parameters, unit 120.80 (dt, 2J(RhC) = 12.5, 3J(PC) = 2.4 Hz, CGCR), 99.90 weights, Enraf-Nonius SDP).34 The positions of the ylide(br, s, C N z ) , 84.72 (dt, 'J(RhC) = 55.0, 2J(PC) = 16.2 Hz, hydrogen atom H was located in the difference-FourierCGCR), 32.62 (s, CCH3), 29.99 (s, CCH3), 23.95 (vt, N = 18.6 synthesis and isotropically refined. The position of the other Hz, PCHCH31, 19.94, 19.74 (both s, PCHCH3). 31PNkfR (C6D6, hydrogen atoms were calculated according to ideal geometry 81.0 MHz): 6 38.11 (d, 'J(RhP) = 127.9 Hz). Preparation of truns-[Rh(CGC-t-Bu)(N2C(H)(COPh)}- (distance C-H 0.95 A) and refined using the riding method. R = 0.032, R, = 0.035; refledparameter ratio 7.96; residual (P-i-Prs)~] (15). A solution of 7 (100 mg, 0.19 mmol) in 5 mL electron density +0.530/-0.475 eV A-3. of pentane was treated as described for 8 with a solution of Computational Methods. The calculations have been PhC(=O)CHN2 (30 mg, 0.20 mmol) in 2 mL of pentane. carried out using effective core potentials (ECP) for Rh, P, and Orange-red crystals were obtained; yield 114 mg (93%); mp C1. The quasirelativistic ECP for Rh has a large valence-shell 126 "C dec. Anal. Calcd for C32Hb~N20P2Rh:C, 59.07; H, basis set (311111/22111/411).35aThe valence-shell basis sets 8.83; N, 4.31. Found: C, 59.90; H, 9.40; N, 4.22. IR (KBr): for P and C1 have DZ+P quality (31/31/1).35bFor C and 0 a Y(C=C)2105, v(N=N) 1935 cm-'. 'H NMR (c6D6,200 MHz): standard DZ+P basis set has been used, and for H a DZ basis 6 7.96-6.95 (m, 5H, C6r,), 2.52 (m, 6H, PCHCH3), 1.43 (s, set has been used.36 The geometry optimization was performed l H , NzCH), 1.39 (s, 9H, C(CH3)3),1.25 (dvt, J(HH) = 6.5, N = at the MP2 level (Moller-Plesset perturbation theory termi13.7 Hz, 18H, PCHCH3), 1.17 (dvt, J(HH) = 6.6, N = 12.8 Hz, nated at second order)37using the program TURBOMOLE.3s 18H, PCHCH3). 13C NMR (C6D6, 50.3 MHz): 6 151.83 (s, c=o),138.51, 129.37, 128.20, 126.64 (all s, C6H5), 119.66 (dt, Acknowledgment. We thank the Deutsche For%T(RhC)= 12.0, 3J(PC) = 2.0 Hz, C=CR), 85.04 (dt, WRhC) = 54.6, 2J(PC)= 15.7 Hz, C=CR), 81.39 (br, s, CN2), 32.63 (s, schungsgemeinschaft (SFB 347) and the Fonds der CCH3), 30.07 (s, CCHs), 23.95 (vt, N = 17.3 Hz, PCHCH3), Chemischen Industrie for financial support, and in 19.87, 19.71 (both S, PCHCH3). 31PNMR (C6D6, 81.0 MHz): particular Degussa AG for various gifts of chemicals. 6 37.39 (d, 'J(RhP) = 126.4 Hz). We also gratefully acknowledge support by Mrs. M.-L. Reaction of 7 with PhCHN2. A solution of 7 (71 mg, 0.13 Schafer and Dr. W. Buchner (NMR spectra), Mrs. A. mmol) in 5 mL of pentane was treated at -78 "C with a Burger, Mrs. R. Schedl, and C. P. Kneis (elemental solution of PhCHN2 (16 mg, 0.13 mmol) in 3 mL of pentane analyses and DTA), and Dr. J. Wolf for helpful discusand with continuous stirring slowly warmed up to room sions. temperature. At ca. -30 "C the color changed from violet to green. The solution was concentrated to 2 mL in vacuo and SupplementaryMaterial Available: Tables giving crysthen stored at -78 "C. A brown solid precipitated which was tal data and data collection and refinement parameters, all filtered off, washed with pentane (-30 "C), and dried in vacuo. bond distances and angles, least-square planes and deviations The solid was identified by 'H- and 31P-NMR spectroscopy as therefrom, anisotropic thermal parameters, and positional a 1:3 mixture of truns-[Rh(C~C-t-Bu)(N2CHPh)(P-i-Pr3)21(16) parameters for 4 (13 pages). Ordering information is given and truns-[Rh(C~Ct-Bu)(Nz)(P-i-Pr3)21(17). Further attempts on any current masthead page. to separate the two products failed. lH NMR spectra at OM940714G variable temperature indicated that a t -40 "C primarily the complex 16 was formed, which at 0 "C decomposed to give 17. (34) Frenz, B. A. The Enraf-Nonius CAD4 SDP-a real time system Data for 16: IR (C6H6): Y(C=C)2060, v(N=N) 1935 cm-'. 'H for concurrent X-ray data collection and structure determination. In NMR (C&, 200 MHz): 6 4.14 (s, l H , N&H), 2.46 (m, 6H, Computing in Cvstallography; Delft University Press: Delft, Holland, PCHCH3), 1.33 (dvt, J(HH) = 6.0, N = 12.8 Hz, 36H, 1978;pp 64-71: (35) (a) Dolg, M.; Wedig, U.;Stoll, H.; Preuss, H. J . Chem. Phys. PCHCH3), 1.27 (s, 9H, C(CH3)3), signal of C&5 not exactly 1987.86. 866-872. (b) Bermer. A.: Dole. M.: Kiichle. W.: Stoll, H.: located. 31PNMR (CsD6, 81.0 MHz): 6 46.96 (d, 'J(RhP) = Preuss, H.Mol. Phys. 1993; 80,' 1431-fi41. The exponents of the 136.6 Hz). Data for 17: IR (C6H6): v(NEN) 2120 cm-'. d-type polarization functions are 0.55 for P and 0.75 for C1. NMR (CsD6,200 MHz): 6 2.42 (m, 6H, PCHCHs), 1.31 (dvt, (36)(a) Huzinaga, S., Ed. Gaussian Basis Sets for Molecular Calculations; Elsevier: Amsterdam, 1984. (b) Dunning, T. H., Jr. J . J(HH) = 5.8, N = 13.1 Hz, 36H, PCHCH3), 1.29 (s, 9H, Chem. Phys. 1970,53,2823-2833. C(CH3)3). 31PNMR (C6D6, 81.0 MHz): 6 39.73 (d, 'J(RhP) = (37) (a) Mgller, C.; Plesset, M. S. Phys. Reu. 1943,46,618-622. (b) 127.9 Hz). Binkley, J. S.; Pople, J . A. Int. J . Quantum Chem. 1976,9,229-236. X-ray Structural Analysis of 4. Single crystals were (38) (a) Haser, M.; Ahlrichs, R. J . Comput. Chem. 1989,10, 104111. (b) Ahlrichs, R.;Bar, M.; Haser, M.; Horn, H.; Kolmel, C. Chem. grown from hexanehenzene. Crystal data (from 23 reflections, Phys. Lett. 1989,162, 165-169. ( c ) Horn, H.; Weiss, H.; Haser, M.; 10" < 9 < 14"): monoclini?, space group P21/c (No. 14), u = Ehrig, M.; Ahlrichs, R. J . Comput. Chem. 1991,12, 1058-1064. (d) 11.280(3)A, b = 15.201(2)A, c = 17.041(5)A, ,B = 92.36(1)", V Haser, M.; Almlof, J.; Feyereisen, M. W. Theor. Chim. Acta 1991,79, = 2919(1) A3,2 = 4, d&d = 1.312 g cm+, p(Mo &I = 7.9 cm-'; 115-122. (e) Haase, F.; Ahlrichs, R. J . Comput. Chem. 1993,14,907912. crystal size 0.25 x 0.15 x 0.15 mm; Enraf-Nonius CAD4 '
