Imido complexes, transition metal

Phosphinimato complexes transition metals, 122,125 bonding, 124 IR spectroscopy, 124 reactions, 125 structure, 124 synthesis, 123 Phosphini mines imido metal complexes synthesis from, 167 Phosphoglucomutase zinc complexes, 965 Phospholes... 

Reactions with Transition-Metal Compounds. The numerous pubhshed products of reactions of transition-metal compounds with a2iridines can be divided into complexes in which the a2iridine ring is intact, compounds formed by reaction of a2iridine with the ligands of a complex, and complexes in which the a2iridine molecule is fragmented (imido complexes). 

W. A. Nugent and J. M. Mayer, Metal-Eigand Multiple Bonds The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Jilkylidene, orJilkylidyne Eigands,Jolm. Wiley Sons, Inc., New York, 1988. Contains electronic and molecular stmcture, nmr, and ir spectroscopy, reactions, and catalysis. 

Titanium imido complexes supported by amidinate ligands form an interesting and well-investigated class of early transition metal amidinato complexes. Metathetical reactions between the readily accessible titanium imide precursors Ti( = NR)Cl2(py)3 with lithium amidinates according to Scheme 84 afforded either terminal or bridging imido complexes depending on the steiic bulk of the amidinate anion. In solution, the mononuclear bis(pyridine) adducts exist in temperature-dependent, dynamic equilibrium with their mono(pyiidine) homologs and free pyridine. 

Organometallic complexes of the /-elements have been reported that will perform both intra-and intermolecular hydroamination reactions of alkenes and alkynes, although these lie outside of the scope of this review.149-155 Early transition metal catalysts are not very common, although a number of organometallic systems exist.156-158 In these and other cases, the intermediacy of a metal imido complex LnM=NR was proposed.159,160 Such a species has recently been isolated (53) and used as a direct catalyst precursor for N-H addition to alkynes and allenes (Scheme 35).161,162... 

The resulting complexes 59 display catalytic activities in ROMP that exceed even the performance of molybdenum-imido system 50 (Fig. 3), which has been considered as intrinsically more active than late-transition metal systems, but also more sensitive toward polar functionalities, water, and air. Thus, to combine... 

An excellent review of transition metal imido complexes appeared in 1980 (260). Transition metal imido complexes (NR R = H, alkyl, or aryl) are most common for Second and Third Row metals, but relatively rare for First Row metals. Three classes of imido complex are known. The majority of imido complexes are monomeric containing a terminal imido group which may adopt either a linear configuration (M=N—R) containing a formal metal-nitrogen triple bond as in [Os(N-fBu)03] and rans-[M(NH)X(dppe)2]+ (M = Mo or W X = CH30,... 

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