Crystal Structure Of (C9h17n2)(3)[Bi2i9]

Single crystals of tris (2,3,4,6,7,8,9,10-octahydropyrimido [1,2-a] azepin-1 -ium) tri-mu(2)-iodido-bis[triiodidobismuth(III)], (C9H17N2)(3)[Bi2I9], were prepared by a solvothermal method, heating a mixture of BiI3, KI, 1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU) and ethanol at 443 K for six days. The asymmetric unit of the title compound, which crystallizes in the monoclinic space group P2(1/c), contains one [Bi2I9](3-) anion and three protonated DBUH+ moieties. The dinuclear [Bi2I9](3-) anions, which are composed of face-sharing BiI63- octahedra, are packed in columns parallel to the [010] direction, and separated by protonated DBUH+ moieties. The optical band gap of (C9H7N2)(3)Bi2I9 is 2.1 eV.