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Syntheses and Molecular Structures of New Calix[4]arene Molybdenum and Tungsten Complexes
Author(s) -
Attner Juri,
Radius Udo
Publication year - 2001
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/1521-3765(20010216)7:4<783::aid-chem783>3.0.co;2-z
Subject(s) - molybdenum , alkoxide , disproportionation , triethylamine , adduct , chemistry , tungsten , medicinal chemistry , halide , hexa , crystallography , polymer chemistry , stereochemistry , inorganic chemistry , catalysis , organic chemistry
An unusual disproportionation reaction of the molybdenum( IV ) and tungsten( IV ) chlorides [MCl 4 L 2 ] (M=Mo, L=Et 2 S, Et 2 O; M=W; L=Et 2 S) in the presence of p‐t Bu‐calix[4]arene (Cax(OH) 4 ) and triethylamine leads to d 0 complexes [(CaxO 4 ){CaxO 2 (OH) 2 }M] ( 1 ) and d 3 compounds (HNEt 3 ) 2 [(CaxO 4 ) 2 M 2 ] ( 2 ). Complexes 1 a (M=Mo), 1 b (M=W), and the HCl adduct of 2 a (M=Mo) have been structurally characterized. Compound 1 a represents one of the few examples of a well‐characterized molybdenum( VI ) hexa‐alkoxide complex of the type [Mo(OR) 6 ]. Isolation and structural characterization of the side product [(CaxO 4 W){ κ 2 (O)‐ κ 1 (O)‐CaxO 3 (OH)}(CaxO 4 WCl)] ( 3 ) suggests the intermediacy of chloro‐containing calix[4]arene complexes in these reaction mixtures. The reaction of 1 a with HCl provides [CaxO 4 MoCl 2 ] ( 4 a ), the first well‐defined example of a mixed molybdenum( VI ) alkoxide halide compound of the general formula [MoCl x (OR) 6− x ].