Transition Metals and Metal Carbonyls

Since 1939 I have come into closer contact with the organometallic chemistry of transition metals than I did during my first attempts to arylate Fe(CN)g , My attention was attracted to the paper by Job and Cassal, who synthesized chromium, molybdenum, and tungsten carbonyls by a simultaneous reaction of the halides with carbon monoxide and Grignard compounds. 

Tungsten or molybdenum hexacarbonyls were also found by us to be readily prepared from WClf, or M0CI5, respectively, with iron pentacar-bonyl. The yield was 75% with V(CO)g 210) and 30% with Mo(CO)5 211), higher pressures of CO being necessary in the latter case. As far as I know, our discoveries of 1939 were a starting point for the industrial preparation of metal carbonyls through the carbonylation of metal chlorides accomplished in various countries. 

Our later investigations in collaboration with Freidlina and Chukovskaya 212) showed that metal carbonyls, especially iron pentacarbonyl, were 

The carbonyl work was continued in the 1960s when the ferrocene studies (see below) were extending the organometallic chemistry of transition metals. Here I will mention manganese-rhenium decacarbonyl 213) obtained by us through the reation 

This carbonyl, in which the metal-metal bond is covalent (Struchkov s and our data) attracted our attention to related compounds which could be readily prepared from salts such as NaMn(CO)5, NaRe(CO)5, NaCo(CO)4, or CpMo(CO)3Na. In collaboration with Anisimov, Kolobova, Khandozhko, Zakharova, Antonova, and others (214-226), we obtained many di- and polymetallic carbonyl-containing compounds through reactions of the salts with SiCl4, GeCl4, or SnCl4. Typical compounds obtained were 

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