From U(IV) double-decker phthalocyanine with stacked UPc2 sandwiches to unstacked ones

The uranium diphthalocyanine complex with the composition of [UPc2]·2DBU·(CH3)2CO has been obtained by recrystallisation of [UPc2](I3)2/3 in DBU (1,8-diazabicyclo[4.5.0]undec-7-ene) during slow dilution with acetone. The [UPc2]·2DBU·(CH3)2CO complex crystallises in the Pna21 space group of the orthorhombic system with four molecules in the unit cell. In contrast to the stacked structure of [UPc2](I3)2/3 the structure of [UPc2]·2DBU·(CH3)2CO contains separated and unstacked UPc2 sandwiches. The [UPc2]·2DBU·(CH3)2CO complex dissolved in benzene, in 1-choronaphthalene and in DBU has been characterised by the UV–Vis spectroscopy. Some remarks on the stability of the complex in these solutions as well as its transformation to uranium monophthalocyanine have been made.