Diplatinum(III) complexes with four bridging 1-methylcytosinato nucleobases derived from a mononuclear trans-(NH3)2PtII complex and CuII.
A heteronuclear complex of composition trans-[(NH(3))(2)Pt(N4-1-MeC(-)-N3)(2)Cu(H(2)O)(2)](ClO(4))(2) (1a), with 1-MeC(-) = 1-methylcytosinate, has been prepared and characterized by X-ray crystallography. 1a (Cu,Pt) is a linkage isomer of a previously described compound with the two metals inverted (Pt,Cu). The intermetallic distances are significantly different in the two types of compounds, 2.6109(9) A in 1a, yet 2.49-2.56 A in several forms of the linkage isomer. When heated in water in the presence of air, 1a is converted in low yield into diplatinum(III) compounds [(H(3)N)Pt(1-MeC(-)-N3,N4)(4)Pt(NH(3))](2+) (2a) and [(H(2)O)Pt(1-MeC(-)-N3,N4)(4)Pt(NH(3))](2+) (2b), which were crystallized as ClO(4)(-) salts. In a modified procedure a third representative of this group of diplatinum(III) compounds, [(O(2)N)Pt(1-MeC(-)-N3,N4)(4)Pt](+) (2c) was isolated. All three compounds contain the four bridging 1-MeC ligands in a head,tail,head,tail arrangement with Pt-Pt distances (2.4516(7)-2.4976(9) A) that are the shortest ones among diplatinum(III) compounds containing nucleobases.
Müller
Jens
J
Fachbereich Chemie, Universität Dortmund, D-44221 Dortmund, Germany. jens.mueller@uni-dortmund.de
Freisinger
Eva
E
Sanz Miguel
Pablo J
PJ
Lippert
Bernhard
B
D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009944:Organoplatinum Compounds / Q000138:chemical synthesis*; D010084:Oxidation-Reduction; D011743:Pyrimidines / Q000138:chemical synthesis*; D012996:Solutions
D007202:Indicators and Reagents; D009944:Organoplatinum Compounds; D011743:Pyrimidines; D012996:Solutions; C482211:diammineplatinum(II)bis(N11-methylcytosinate-N3)(diaquacopper(II)); D003300:Copper