Cadmium(II) thio- and selenocyanate complexes of 3,3'-bis(1,2,4-triazol-4-yl)-1,1'-biadamantane, a ligand designed with an 'extended nanodiamond' aliphatic platform.

In the structures of the Cd(II) pseudohalide coordination polymer poly[[diaquabis[mu(2)-3,3'-bis(1,2,4-triazol-4-yl)-1,1'-biadamantane-kappa(2)N(1):N(1')]cadmium(II)] dithiocyanate dihydrate], {[Cd(C(24)H(32)N(6))(2)(H(2)O)(2)](NCS)(2).2H(2)O}(n), (I), and the isomorphous selenocyanate analogue, {[Cd(C(24)H(32)N(6))(2)(H(2)O)(2)](NCSe)(2).2H(2)O}(n), (II), the Cd(II) cations occupy inversion centres and have octahedral CdN(4)O(2) environments, completed by four N atoms of the organic ligands [Cd-N = 2.316 (2) and 2.361 (2) A for (I), and 2.313 (3) and 2.372 (3) A for (II)] and two trans-coordinated aqua ligands [Cd-O = 2.3189 (15) A for (I) and 2.323 (2) A for (II)]. In each compound, the ligand displays a bidentate N(1):N(1')-bridging mode, connecting the metal centres at a distance of 14.66 A into two-dimensional nets of (4,4)-topology, while the uncoordinated thio(seleno)cyanate anions reside inside the net cavities. Hydrogen bonding between the water molecules, anions and 1,2,4-triazole N atoms supports the tight packing, with an interlayer distance of 6.09 A.