THE DICHLOROPLATINUM(II) COMPLEX OF 5,5,7-TRIMETHYL-1,4-DIAZACYCLOHEPTANE - PREPARATION, CRYSTAL-STRUCTURE AND BINDING TO NUCLEOTIDES AND DNA

The preparation of [Pt(tmdz)Cl-2] (tmdz = 5,5,7-trimethyl-1,4-diazacyc loheptane) is described. The crystal structure has been determined by X-ray diffraction methods and refined to an R value of 0.048 (764F). T he crystals are triclinic, space group P (1) over bar, a 8.023(2), b 1 0.874(4), c 14.207(3) Angstrom, alpha 95.34(3), beta 94.96(2), gamma 9 4.97(3)degrees. N.m.r. studies and molecular mechanics methods show th at only one diastereomer of the complex-that observed in the crystal s tructure-is energetically accessible. In total DNA binding studies, [P t(tmdz)Cla] binds less effectively and at a lower rate than cisplatin. The complex reacts with dG and d(GpG) to form a variety of isomeric p roducts, as indicated by h.p.l.c. analysis.