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New Oxovanadium(IV) Complexes with Mixed Ligands ‐ Synthesis, Thermal Stability, and Crystal Structure of (VO) 2 (acac) 2 (μ‐OEt) 2 and (VO) 2 (thd) 2 (μ‐OEt) 2
Author(s) -
Ahmed M. A. K.,
Fjellvåg H.,
Kjekshus A.,
Klewe B.
Publication year - 2004
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.200400369
Subject(s) - crystal structure , chemistry , valence (chemistry) , crystallography , vanadium , square pyramidal molecular geometry , thermal stability , single crystal , hydrogen bond , stereochemistry , molecule , inorganic chemistry , organic chemistry
Synthesis, crystal structure, thermal stability, and magnetic properties of the new oxovanadium(IV) complexes [(VO) 2 L 2 (μ‐OEt) 2 ] with mixed β‐diketonato [L = acac = C 5 H 7 O 2 ‐ or L = thd = C 11 H 19 O 2 ‐ ] and ethanolato (OEt) ligands are reported. The structure determinations of (VO) 2 (acac) 2 (μ‐OEt) 2 [ P 2 1 / c , with a = 14.775(2), b = 8.788(1), c = 15.742(2) Å, β = 112.43(1)°] and (VO) 2 (thd) 2 (μ‐OEt) 2 [ $P{\bar 1}$ , with a = 8.871(3), b = 9.988(4), c = 10.299(4) Å, α = 73.51(1), β = 68.70(1), γ = 65.85(1)°] are based on single‐crystal X‐ray diffraction data collected at 105 K. Structure data for VO(acac) 2 and VO(thd) 2 are redetermined at 105 and 295 K. (VO) 2 (acac) 2 (μ‐OEt) 2 and (VO) 2 (thd) 2 (μ‐OEt) 2 comprise binuclear five‐coordinated molecular units. The configuration of five oxygen atoms around a central vanadium atom is approximately square pyramidal in all the four studied complexes. (VO) 2 (thd) 2 (μ‐OEt) 2 exhibits conspicuous changes in unit‐cell dimensions (expansion in a and c , shrinkage in b , and appreciable variation in α, β, and γ) on going from 105 to 295 K, which appear to reflect adjustments in the configuration of its ( anti ‐arranged) ligands. The interatomic distances in the crystal structures are analyzed in terms of the bond‐valence concept. The four‐valent state of vanadium is verified by magnetic susceptibility measurements. All complexes are subject to sublimation.