A number of mesogenic bis[4-(dodecyloxy)-N-(4'-R(n)-phenyl)salicylideneiminato]oxovanadium(IV) complexes (1-7, R(n) = CH3, C2H5, C3H7, C4H9, C6H13, OC6H13, C8H17, respectively) have been synthesized and characterized by polarizing microscope observations, DSC measurements, X-ray diffraction, and EPR spectroscopy. These compounds are thermally stable and to not decompose on melting. Complexes 1-5 show two different solid phases K1 and K2. In addition, 4 and 5 exhibit a liquid-crystalline smectic A phase (monotropic in 4 and enantiotropic in 5). On the other hand, 6 and 7 along with a single solid phase, display a smectic C (enantiotropic in 6 and monotropic in 7) and an enantiotropic smectic A phase. Variable-temperature EPR spectra are accounted for on the basis of paramagnetic metal ions experiencing different magnetic environments. For each mesophase, matching X-ray, and EPR data, the molecular packing mode is suggested. Comparing 1-7 with the homologous copper complexes, the contribution of the metallic center to the mesomorphic properties is discussed.
Transitions Metals Complexed to Ordered Mesophases. Synthesis, Mesomorphism, and X-ray and EPR Characterization of a Homologous Series of N-(4-Dodecyloxysalicylidene)-4'-alkylanilines Complexed to Oxovanadium(IV) / M., Ghedini; S., Morrone; R., Bartolino; V., Formoso; Francescangeli, Oriano; B., Yang; D., Gatteschi; C., Zanchini. - In: CHEMISTRY OF MATERIALS. - ISSN 0897-4756. - 5 (6),:(1993), pp. 876-882. [10.1021/cm00030a026]
Transitions Metals Complexed to Ordered Mesophases. Synthesis, Mesomorphism, and X-ray and EPR Characterization of a Homologous Series of N-(4-Dodecyloxysalicylidene)-4'-alkylanilines Complexed to Oxovanadium(IV)
FRANCESCANGELI, ORIANO;
1993-01-01
Abstract
A number of mesogenic bis[4-(dodecyloxy)-N-(4'-R(n)-phenyl)salicylideneiminato]oxovanadium(IV) complexes (1-7, R(n) = CH3, C2H5, C3H7, C4H9, C6H13, OC6H13, C8H17, respectively) have been synthesized and characterized by polarizing microscope observations, DSC measurements, X-ray diffraction, and EPR spectroscopy. These compounds are thermally stable and to not decompose on melting. Complexes 1-5 show two different solid phases K1 and K2. In addition, 4 and 5 exhibit a liquid-crystalline smectic A phase (monotropic in 4 and enantiotropic in 5). On the other hand, 6 and 7 along with a single solid phase, display a smectic C (enantiotropic in 6 and monotropic in 7) and an enantiotropic smectic A phase. Variable-temperature EPR spectra are accounted for on the basis of paramagnetic metal ions experiencing different magnetic environments. For each mesophase, matching X-ray, and EPR data, the molecular packing mode is suggested. Comparing 1-7 with the homologous copper complexes, the contribution of the metallic center to the mesomorphic properties is discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
