Synthesis and Structure of a Series of New d 1 -Aryl Imido-Vanadium(IV) Complexes Stabilized by N-Donor Ligands Christian Lorber,* Robert Choukroun, and Bruno Donnadieu Laboratoire de Chimie de Coordination, CNRS UPR 8241, 205 route de Narbonne, 31077 Toulouse Cedex 04, France Received May 3, 2002 A family of new coordination vanadium(IV) compounds supported by a terminal or bridged aryl imido ligand are reported. Reaction of V(NMe 2 ) 4 with anilines ArNH 2 , where Ar ) 2,6-i-Pr 2 -C 6 H 3 , 2,6-Me 2 -C 6 H 3 , Ph, 2,6-Cl 2 -C 6 H 3 , and C 6 F 5 , afforded the diamagnetic imido-bridged complexes [V(NAr)(NMe 2 ) 2 ] 2 (1a-e). Chlorination of 1a-e with trimethylchlorosilane afforded complexes 2a-e formulated as [V(dNAr)Cl 2 (NHMe 2 ) x ] n . One-pot reaction of V(NMe 2 ) 4 with ArNH 2 in the presence of an excess of trimethylchlorosilane gave the five-coordinate compound [V(dNAr)- Cl 2 (NHMe 2 ) 2 ](3a-e). Reaction of 3a-e with pyridine, bipyridine (bipy), or N,N,N′,N′-tetramethylethylenediamine (tmeda) gave respectively the six-coordinate tris- or bis(pyridine) adducts [V(dNAr)Cl 2 (Py) 3 ](4a-e) or [V(dNAr)- Cl 2 (Py) 2 (NHMe 2 )] (5a), bipyridine complexes [V(dNAr)Cl 2 (bipy)(NHMe 2 )] (5a-e) and [V(dNAr)Cl 2 (bipy)(Py)] (9a), and tmeda adduct [V(dNAr)Cl 2 (tmeda)(NHMe 2 )] (10a). Moreover, five-coordinate complexes free of NHMe 2 ligands, such as [V(dNAr)Cl 2 (Py) 2 ](5a), [V(dNAr)Cl 2 (bipy)] (8a), and [V(dNAr)Cl 2 (tmeda)] (11a), were directly prepared starting from precursors 2a-e. All compounds were totally characterized by spectroscopic methods (IR, 1 H NMR for diamagnetic complexes, and EPR for paramagnetic complexes), elemental analysis, magnetism, and single- crystal X-ray diffraction studies for 1b, 3a, 3d, 4b, 4d, 7c, 10a, and 11a. Introduction The last two decades have witnessed a strong interest in the coordination chemistry of transition metal complexes containing imido ligands [NR] 2- (R ) alkyl or aryl). 1,2 The dianionic π-donor terminal imido functional group is in- volved in a rich chemistry that can be subdivided into two types: the first concerns reactions in which the imido group acts as a spectator ligand, 1,2 the [NR] 2- moiety being isolobal with [C 5 H 5 ] - 3 (e.g. in alkene methathesis 4 or olefin polymerization 5-7 ), but the MdNR linkage itself can also be involved in a variety of transformations such as imine metathesis, 8 oxo-imido exchange, 9 C-H activation, 10 reac- tions with unsatured C-C 11 or C-X bonds, 12 ... As part of an ongoing study of vanadium alkoxide, 13 diamide, 14 poly-yne, 15 or iminoacyl 16 complexes, we recently described the synthesis and molecular structure of the new terminal imido complex [V(NdAr)Cl 2 (NHMe 2 ) 2 ] (Ar ) 2,6- i-Pr 2 -C 6 H 3 ), 7 one of the very few Cp-free vanadium(IV) * E-mail: lorber@lcc-toulouse.fr. (1) Wigley, D. E. In Progress in Inorganic Chemistry; Karlin, K. D., Ed.; Interscience: New York, 1994; Vol. 42, pp 239-482. (2) Nugent, W. A.; Mayer, J. M. In Metal-Ligand Multiple Bonds; Wiley- Interscience: New York, 1998. (3) Williams, D. N.; Mitchell, J. P.; Poole, A. D.; Siemeling, V.; Clegg, W.; Hockless, D. C. R.; O’Neil, P. A.; Gibson, V. C. J. Chem. Soc., Dalton Trans. 1992, 739-751. (4) Schrock, R. R. Acc. Chem. Res. 1990, 23, 158-165. (5) Chan, M. C. W.; Chen, K. C.; Dalby, C. I.; Gibson, V. C.; Kohlmann, A.; Little, I. R.; Reed, W. Chem, Commun. 1998, 1673-1674. (6) Scheuer, S.; Fischer, J.; Kress, J. Organometallics 1995, 14, 2627- 2629. (7) Lorber, C.; Donnadieu, B.; Choukroun, R. J. Chem. Soc., Dalton Trans. 2000, 4497-4498. (8) (a) Meyer, K. E.; Walsh, P. J.; Bergman, R. G. J. Am. Chem. Soc. 1995, 117, 974-985. (b) Meyer, T. Y.; Kantrell, G. K. Chem. Commun. 1997, 1551-1552. (c) Meyer, T. Y.; Kantrell, G. K. Organometallics 1997, 16, 5381-5883. (d) McInnes, J. M.; Mountford, P. Chem. Commun. 1998, 1669-1670. (9) Nugent, W. A. Inorg. Chem. 1983, 22, 955-969. (10) (a) Bennet, J. L.; Wolczanski, P. T. J. Am. Chem. Soc. 1997, 119, 10696-10709. (b) Lee, S. Y.; Bergman, R. G. J. Am. Chem. Soc. 1995, 117, 5877-5878. (11) (a) Tro ¨sch, D. J. M.; Collier, P. E.; Bashall, A.; Gade, L. H.; McPartlin, M.; Mountford, P.; Radojeric, S. Organometallics 2001, 20, 3308- 3313. (b) Walsh, P. J.; Baranger, A. M.; Bergman, R. G. J. Am. Chem. Soc. 1992, 114, 1708-1719. (c) Polse, J. L.; Andersen, R. A.; Bergman, R. G. J. Am. Chem. Soc. 1998, 120, 13405-13414. (d) Chong, A. O.; Oshima, K.; Sharpless, K. B. J. Am. Chem. Soc. 1977, 99, 3420-3426. (e) Lee, S. Y.; Bergman, R. G. Tetrahedron 1995, 51, 4255-4276. (12) (a) Pugh, S. M.; Tro ¨sch, D. J. M.; Wilson, D. J.; Bashall, A.; Clocke, F. G. N.; Gade, L. H.; Hitchcock, P. B.; McPartlin, M.; Nixon, J. F.; Mountford, P. Organometallics 2000, 19, 3205-3210. (b) Meisel, I.; Hertl, G.; Weiss, K. J. Mol. Catal. 1986, 36 159-162. Inorg. Chem. 2002, 41, 4217-4226 10.1021/ic020312y CCC: $22.00 © 2002 American Chemical Society Inorganic Chemistry, Vol. 41, No. 16, 2002 4217 Published on Web 07/16/2002