Synthesis,characterization, and structural investigation of New η5-Cyclopentadienylbis-8-hydroxyquinolinatometal(IV) Complexes |
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Authors: | I. Demakopoulos N. Klouras C. P. Raptopoulou A. Terzis |
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Abstract: | By the interaction of M(η5-C5H4R)2Cl2 (M = Zr, Hf; R = H, Me, SiMe3) and 8-hydroxyquinoline (oxH) or 5-chloro-8-hydroxyquinoline (ox′H) in dichloromethane solution at 20°C, the compounds M(η5-C5H4R)Clox2 and M(η5-C5H4R)Clox2′ were prepared respectively. A similar reaction of Ti(η5-C5H5)Cl3 with ox′H in acetonitrile solution gave Ti(η5-C5H5)Clox2′. All complexes were characterized by elemental microanalysis and by IR and 1H NMR spectroscopy. X-ray analysis of M(η5-C5H5R)Clox2′ (M = Ti, Hf) shows that these molecules may be described in terms of stereochemistry of eight-coordination approximating dodecahedral geometry more closely than octahedral geometry. With respect to octahedral coordination, the nitrogen atoms lie in a cis-configuration and the oxygen atoms in a trans-configuration. Dichloromethane molecules co-crystallize with the hafnium complex and occupy a position on the 2-fold axis. The structural results are compared with those in related compounds. |
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Keywords: | Metallocene bis-8-hydroxyquinolinates Titanium Zirconium Hafnium Crystal structure |
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