Bis(&mgr;-hexamethylenetetramine)bis(aquadibromocadmium)diaquadibromo cadmium dihydrate
The title compound, poly[[diaquadibromocadmium-&mgr;-(1,3,5, 7-tetraazatricyclo[3.3.1.1(3, 7)]decane-N(1):N(5))-aquacadmium-di-&mgr;-bromo-aquacadmium-&mgr;-(1, 3,5,7-tetraazatricyclo[3.3.1.1(3, 7)]decane-N(1):N(5))-di-&mgr;-bromo] dihydrate], [Cd(3)Br(6)(C(6)H(12)N(4))(2)(H(2)O)(4)].2H(2)O, is made up of two-dimensional neutral rectangular coordination layers. Each rectangular subunit is enclosed by a pair of Cd(3)(&mgr;(2)-Br)(6)(H(2)O)(3) fragments and a pair of (&mgr;(2)-hmt)Cd(H(2)O)(2)Br(2)(&mgr;(2)-hmt) fragments as sides (hmt is hexamethylenetetramine). The unique Cd(II) atom in the Cd(2)Br(2) ring in the Cd(3)(&mgr;(2)-Br)(6)(H(2)O)(3) fragment is in a slightly distorted octahedral CdNOBr(4) geometry, surrounded by one hmt ligand [2.433 (5) A], one aqua ligand [2.273 (4) A] and four Br atoms [2.6409 (11)-3.0270 (14) A]. The Cd(II) atom in the (&mgr;(2)-hmt)Cd(H(2)O)(2)Br(2)(&mgr;(2)-hmt) fragment lies on an inversion center and is in a highly distorted octahedral CdN(2)O(2)Br(2) geometry, surrounded by two trans-related N atoms of two hmt ligands [2.479 (5) A], two trans-related aqua ligands [2.294 (4) A] and two trans-related Br atoms [2.6755 (12) A]. Adjacent two-dimensional coordination sheets are connected into a three-dimensional network by hydrogen bonds involving lattice water molecules, and the aqua, bromo and hmt ligands belonging to different layers.
Tong
ML
School of Chemistry and Chemical Engineering, Zhongshan University, Guangzhou 510275, People's Republic of China.
Zheng
SL
Chen
XM