Cyclobutadiene and its deviations,which are appeared in organic sysnthesis as intermediates,are difficult to be synthesized and isolated due to its antiaromacity and destabliazation.Density functional
Bimolecular nucleophilic substitution (SN2) reaction is ubiquitous in chemistry[1].Compared to the extensive research on the SN2 process at carbon and nitrogen,the displacement at phosphorus,denoted a
Hydrothermal reaction of 2,5-di(2,4-dicarboxylphenyl)pyridine(ddpp)with Mn(Ⅱ)acetate in the presence of ammonium oxalate gives rise to a 3-D coordination framework {[Mn4(ddpp)2(μ4-C2O4)·6H2O]·2H2O}n(1