Organometallic diazo compounds

Abstract

Organometallic chemistry has traditionally, by definition, been concerned with the chemistry of metalcarbon-bonded compounds. Nevertheless, there is growing interest in metal-heteroatom bonds such 88 M-N, M-O, M-S, etc., in organometallic compounds. The present article systematically summarizes the literature dealing with transition-metal organometallic compounds havingsome kind of M-N-N skeleton, here broadly classified under the generalized name organometallic “diazo” compounds. This area has not been reviewedpreviouslyasatopic, but mentioncan bemade of some earlier reviews that have discussed some of the typesof compoundsto be covered here. The mostrecent general review of inorganic complexes with miscellaneous nitrogen ligands was published in 1987.’ Others have dealt with organometallic compounds with nitrogen ligands related to reduced dinitrogen,’ aryldiazenido complexes? the N=N group,& diazoalkanesPb trimethylsilyldias,k and substituted hydrazines.‘,C There are useful theoretical papers discussing diazo ligands.6f-h In order to focus the review and to keep it to a reasonable length the discussion will be limited for the most part to the following types of ligands (where R signifies an organic group or H): diazenide (NNR), diazene (RNNR), hydrazide(1-) (NRNR2), hydrazide(2-) (NNRz), and hydrazine (hNNR2). That is to say, the article is concerned with the MNN skeleton in all conceivable permutations of bond orders, stereochemistry, and degrees of substitution in organotransition metal compounds. The simplest ‘diazo” ligand, dinitrogen, will not, however, be discussed, except in instances where a direct relation to subject of the review