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Complexes of the (Tetramethylcyclobutadiene)cobalt Fragment with Boratabenzene Ligands and an Unprecedented Formation of a Borabenzene Complex − Structures of (C 4 Me 4 )Co(3,5‐Me 2 C 5 H 3 BSnMe 3 ) with an Sn−B Bond and of the Dinuclear Complex [(C 4 Me 4 )Co(3,5‐Me 2 C 5 H 3 B)] 2 O
Author(s) -
Herberich Gerhard E.,
Baul Tushar S. Basu,
Englert Ulli
Publication year - 2002
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/1099-0682(20021)2002:1<43::aid-ejic43>3.0.co;2-7
Subject(s) - chemistry , stereochemistry , cobalt , derivative (finance) , ligand (biochemistry) , crystal structure , medicinal chemistry , trimethylamine , crystallography , organic chemistry , receptor , biochemistry , financial economics , economics
The yellow‐orange boratabenzene complex Cb*Co(3,5‐Me 2 C 5 H 3 BNMe 2 ) ( 1 ) (Cb* = C 4 Me 4 ) was readily obtained from [Cb*Co(NCMe) 3 ]PF 6 and Li(TMEDA)(3,5‐Me 2 C 5 H 3 BNMe 2 ). Methanolysis of 1 afforded Cb*Co(3,5‐Me 2 C 5 H 3 BOMe) ( 2 ). Complex 2 reacted with MeLi and with BCl 3 to give the B ‐methyl analogue 3 and the B ‐chloro compound 4 , respectively. The chloro compound 4 reacted with i Bu 2 AlH, TlF, and LiSnMe 3 to afford the B ‐hydrido derivative 5 , the B ‐fluoro complex 6 , and the B ‐(trimethylstannyl) compound 7 , respectively. A single‐crystal structure determination of 7 gave an Sn−B bond length of 2.236(5) Å. The B−O−B‐linked dinuclear complex [(C 4 Me 4 )Co(3,5‐Me 2 C 5 H 3 B)] 2 O ( 8 ) was also characterized structurally. The amino compound 1 underwent an unprecedented quaternization with iodomethane to produce [Cb*Co(3,5‐Me 2 C 5 H 3 BNMe 3 )]I ( 10 ) which possesses a borabenzene−trimethylamine ligand. Compound 10 is the first borabenzene complex of a metal outside the chromium group. When treated with Bu 4 NCN in CH 2 Cl 2 nucleophilic substitution of the NMe 3 group took place to give the B −CN derivative 11 which is the first B ‐cyanoboratabenzene complex.