Tris Hydrate and cis-Dibromo(1,2-diaminocyclohexane)platinium(II)

Article abstract of DOI:10.1107/S0567740881002161

3*H2O (A) is monoclinic, C2/c, Z=8, a=24.31(2), b=12.439(5), c=20.981(9) Angstroem, β= 110.59(5) deg. (B) is monoclinic, C2/c, Z=8, a=15.212(4), b=11.612(5), c=13.268(5) Angstroem, β=121.17(2) deg.The structure of (A) was determined by direct methods and that of (B) by heavy-atom methods.Both were refined by full-matrix least-squares procedures to R=0.059, R_W=0.072 for (A) and R=0.041, R_W=0.056 for (B).The basic structures of the molecular units are similar for the chloro and bromo complexes.Bond lengths are normal.Both structures contain pairs of molecules packed square plane to square plane and hydrogen bonded together through N-H...X (X=Cl, Br) to give relatively short Pt...Pt distances <3.479(1), 3.368(1) Angstroem, (A); 3.511(1) Angstroem, (B)>, but in addition the chloro complex contains a third molecule which is not packed in this way.Hydrogen bonds are important in determining the packing in the chloro complex, but surprisingly the water molecule is not involved in strong hydrogen bonding.