Solid-State Photochemical [2+2] Cycloaddition Reaction of MnII Complexes.

摘要: Three MnII complexes have been synthesized under similar experimental conditions. Of these [Mn2 (benzoate)4 (L)2 ] (where L=4-styrylpyridine or 4spy, 1 and 2-fluoro-4'-styrylpyridine 2F-4spy, 3) are paddlewheel complexes, but crystallized in different space groups. Whereas (3F-4spy)4 (3F-4spy=3-fluoro-4'-styrylpyridine), 4 is a dinuclear complex having stoichiometry from 3 with two pairs of 3F-4spy ligands aligned face-to-face manner. An irreversible phase transition occurs the group P21 /c to C2/c when was heated up 125 °C 2 single-crystal-to-single-crystal fashion ground powder. isomorphous isostructural 3. Complimentary π-π interactions head-to-tail alignment styrylpyridine furnishes 1D aggregates 1-3 which congenial undergo [2+2] cycloaddition reaction UV light. Whereas, 4spy expected provide head-to-head photoproduct. All indeed found be photoreactive. To our surprise, contrary their ZnII analogues, were not photosalient. The percentage volume expansion during photoreaction as determined density measurements, too low (3.2 4.6 % respectively for this behavior.