The first carbene- C, N chelate tetracarbonyl dihalogeno and carbene- C, O chelate tetracarbonyl benzochinone tungsten complexes

• Published in: Journal of organometallic chemistry 2002-05, Vol.651 (1), p.66-71
• Main Authors: Stumpf, Rüdiger, Burzlaff, Nicolai, Weibert, Bernhard, Fischer, Helmut
• Format: Article
• Language: English
• Subjects: Carbene complexes; Chelate complexes; Oxidative decarbonylation; Tungsten complexes
• ISSN: 0022-328X; 1872-8561
• DOI: 10.1016/S0022-328X(02)01255-X

The carbene- C, N chelate tetracarbonyl tungsten complex [(CO) 4 WC(Ph)NHC 5H 4N - o] ( 4), obtained from [(CO) 5WC(Ph)OMe] ( 3) and o-aminopyridine, reacts with iodine by oxidative decarbonylation to give a single isomer of the carbene- C, N chelate tricarbonyl dihalogeno tungsten(II) complex [(CO) 3I 2W C(Ph)NHC 5H 4N - o] ( 5). The analogous reaction of 4 with bromine affords two interconverting isomers of [(CO) 3Br 2 WC(Ph) NHC 5H 4N - o] ( 6). The oxidative decarbonylation of the carbene- C, O chelate tetracarbonyl tungsten complex [(CO) 4 WC(OMe)C 6H 4O Me- o] ( 1) with tetrachloro- o-benzochinone yields the first carbene- C, O chelate tricarbonyl- o-benzochinone tungsten(II) complex 8. The structures of 5 and of [(CO) 4I 2 WC(OMe)C 6H 4O Me- o] ( 2c) were established by X-ray structural analyses. The carbene- C, N chelate tetracarbonyl tungsten(0) complex [(CO) 4 WC(Ph)NHC 5H 4N - o] reacts with X 2 (X=I, Br) by oxidative decarbonylation to give a single isomer (X=I) or two interconverting isomers (X=Br) of the carbene- C, N chelate tricarbonyl diiodo tungsten(II) complex [(CO) 3I 2 WC(Ph)NHC 5H 4N - o]. The first carbene- C, O chelate tricarbonyl- o-benzochinone tungsten(II) complex is obtained by oxidative decarbonylation of [(CO) 4 WC(OMe)C 6H 4O Me- o] with tetrachloro- o-benzochinone.