MO Rationalization of the Synthesis and Structure of V(N-2,6- i Pr 2 C 6 H 3 )Cl(CO) 2 (PMe 3 ) 2 Complex Francisco Montilla, † Norge Cruz Herna ´ ndez, § Diego del Rı ´o, † Javier Ferna ´ ndez Sanz,* ,§ Antonio Pastor, † and Agustı ´n Galindo* ,† Departamento de Quı ´mica Inorga ´ nica, Universidad de Sevilla, Aptdo 553, 41071 Sevilla, Spain, and Departamento de Quı ´mica Fı ´sica, Universidad de Sevilla, Sevilla, 41071 Spain Received July 1, 1999 The sodium amalgam reduction of the compound V(N-2,6- i Pr 2 C 6 H 3 )Cl 3 (dme) in the presence of PMe 3 , under CO (2-3 atm), gives the complex V(N-2,6- i Pr 2 C 6 H 3 )Cl(CO) 2 (PMe 3 ) 2 (1). Spectroscopic data for 1 suggest a trans, trans configuration of the CO and PMe 3 ligands. Density functional theory (DFT) calculations were carried out in order to verify the proposed structure of 1. The adoption of the trans,trans geometry is preferred on the basis of steric arguments. DFT studies of the last steps in the reduction reaction that yields 1 also support the preferential formation of the trans,trans isomer. Introduction Research on transition metal complexes containing organoimido ligands has received great impetus in the last few decades due to the importance of these com- pounds as intermediates and catalysts in a range of reactions. 1,2 In particular, the study of imido vanadium chemistry, which was initiated principally by Preuss and co-workers 3-10 and Maatta and co-workers, 11-14 has attracted considerable attention recently, both from theoretical 15,16 and experimental 17-25 point of views. Although an important amount has been pub- lished 3-14,17-30 about the chemistry of d 0 imido vana- dium complexes, only a few works have been concerned with d 2 species. The first imido complex of trivalent vanadium, namely CpV(NC( t Bu)dCH t Bu)(dmpe), was reported some years ago by Teuben and co-workers. 31 More recently, the same authors reported 32 several d 2 - imido vanadium derivatives starting from CpV(NAr)- (PMe 3 ) 2 . Recently, we have described 33,34 the synthesis and characterization of several d 0 -imido vanadium com- plexes, and as a continuation of these findings, we have explored their reduction reactions toward d 2 compounds. In this paper, we report the preparation and charac- terization of V(N-2,6- i Pr 2 C 6 H 3 )Cl(CO) 2 (PMe 3 ) 2 (1), an example of a d 2 -imido vanadium complex without the stabilizing aid of the cyclopentadienyl ligand. Density functional theory (DFT) studies were carried out with the aim of corroborating the trans,trans geometry of this complex and to account for the ultimate steps in the mechanism of the reduction that shows 1 as the preferred trans,trans isomer. * E-mails: sanz@cica.es and galindo@cica.es. † Departamento de Quı ´mica Inorga ´ nica, Universidad de Sevilla. § Departamento de Quı ´mica Fı ´sica, Universidad de Sevilla. (1) Wigley, D. E. Prog. Inorg. Chem. 1994, 42, 239. (2) Nugent, W. A.; Mayer, J. M. Metal-Ligand Multiple Bonds; Wiley-Interscience: New York, 1988. (3) Tabellion, F.; Nachbauer, A.; Leininger, S.; Peters, C.; Preuss, F.; Regitz, M. Angew. Chem., Int. Ed. Engl. 1998, 37, 1233. (4) Preuss, F.; Hornung, G.; Frank, W.; Reiss, G.; Mu ¨ ller-Becker, S. Z. Anorg. Allg. Chem. 1995, 621, 1663. (5) Preuss, F.; Wieland, T.; Perner, J.; Heckmann, G. Z. Naturforsch. 1992, 47b, 1355. (6) Preuss, F.; Wieland, T.; Gu ¨ nther, B. Z. Anorg. Allg. Chem. 1992, 609, 45. (7) Preuss, F.; Becker, H.; Kaub, J.; Sheldrick, W. S. Z. Naturforsch. 1988, 43b, 1195. (8) Preuss, F.; Noichl, H.; Kaub, J. Z. Naturforsch. 1987, 41b, 1085. (9) Preuss, F.; Becker, H.; Ha ¨ usler, H.-J. Z. Naturforsch. 1987, 42b, 881. (10) Preuss F.; Towae, W. Z. Naturforsch. 1981, 36b, 1130. (11) Wheeler, D. E.; Wu J.-F.; Maatta, E. A. Polyhedron 1998, 17, 969. (12) Hill, P. L.; Yap, G. P. A.; Reingold, A. L.; Maatta, E. A. J. Chem. Soc., Chem. Commun. 1995, 737. (13) Devore, D. D.; Lichtenhan, J. D.; Takusagawa, F.; Maatta, E. A. J. Am. Chem. Soc. 1987, 109, 7408. (14) Maatta, E. A. Inorg. Chem. 1984, 23, 2560. (15) Cundari, T. R. Organometallics 1994, 13, 2987. (16) Cundari, T. R. J. Am. Chem. Soc. 1992, 114, 7879. (17) Chan, M. C. W.; Chew, K. C.; Dalby, C. I.; Gibson, V. C.; Kohlmann, A.; Little, I. R.; Reed, W. Chem. Commun. 1998, 1673. (18) Murphy, V. J.; Turner, H. Organometallics 1997, 16, 2495. (19) Witte, P. T.; Meetsma, A.; Hessen, B.; Budzelaar, P. H. M. J. Am. Chem. Soc. 1997, 119, 10561. (20) Chan, M. C. W.; Cole, J. M.; Gibson, V. C.; Howard, J. A. K. Chem. Commun. 1997, 2345. (21) Schumann, H. Inorg. Chem. 1996, 35, 1808. (22) Scheuer, S.; Fischer, J.; Kress, J. Organometallics 1995, 14, 2627. (23) de With, J.; Horton, A. D. Organometallics 1993, 12, 1493. (24) de With, J.; Horton, A. D. Angew. Chem., Int. Ed. Engl. 1993, 32, 903. (25) de With, J.; Horton, A. D.; Orpen, A. G. Organometallics 1990, 9, 2207. (26) Buijink, J.-K.; Meetsma, A.; Teuben, J. H.; Kooijman, H.; Spek, A. L. J. Organomet. Chem. 1995, 497, 161. (27) Fickes, M. G.; Davis, W. M.; Cummins, C. C. J. Am. Chem. Soc. 1995, 117, 6384. (28) Cummins, C. C.; Schrock, R. R.; Davis, W. M. Inorg. Chem. 1994, 33, 1448. (29) Solan, G. A.; Cozzi, P. G.; Floriani, C.; Chiesi-Villa, A.; Rizzoli, C. Organometallics 1994, 13, 2572. (30) Sundermeyer, J.; Putterlik, J.; Foth, M.; Field, J. S.; Ramesar, N. Chem. Ber. 1994, 127, 1201. (31) Hessen, B.; Buijink, J.-K.; Meetsma, A.; Teuben, J. H.; Helges- son, G.; Håkanson, M.; Jagner, S.; Spek, A. L. Organometallics 1993, 12, 2268. (32) Buijink, J.-K.; Teuben, J. H.; Kooijman, H.; Spek, A. L. Organometallics 1994, 13, 2922. (33) Montilla, F.; Pastor A.; Monge, A.; Gutie ´rrez-Puebla, E.; Gal- indo, A. J. Chem. Soc., Dalton Trans. 1999, 2893. (34) Montilla, F.; Monge, A.; Gutie ´rrez-Puebla, E.; Pastor A.; del Rı ´o, D.; Cruz Herna ´ ndez, N.; Ferna ´ ndez Sanz, J.; Galindo, A. Inorg. Chem. 1999, 38, 4462. 304 Organometallics 2000, 19, 304-308 10.1021/om9905052 CCC: $19.00 © 2000 American Chemical Society Publication on Web 01/04/2000 Downloaded by SPAIN CONSORTIA on July 7, 2009 Published on January 4, 2000 on http://pubs.acs.org | doi: 10.1021/om9905052