474779-33-4Relevant academic research and scientific papers
Reactivity of platina-β-diketones with 1,4-diazabuta-1,3-dienes: Synthesis and characterization of acylplatinum(II) complexes with RN=CMeCMe=NR and RN(H)CH=CHN(R)C(O)Me ligands
Vyater, Armand,Wagner, Christoph,Merzweiler, Kurt,Steinborn, Dirk
, p. 4369 - 4376 (2002)
The dinuclear platina-β-diketone [Pt2{(COMe)2H}2(μ-Cl)2] (la) reacts with 2,3-dimethyl-substituted 1,4-diazabuta-1,3-dienes RN=CMeCMe=NR (R = n-Pr, Ph), yielding the acylplatinum(II) complexes [Pt(COMe)2{(n-Pr)N=CMeCMe=N(n-Pr)}] (2a) and [Pt(COMe)-Cl(PhN=CMeCMe=NPh)] (2b), respectively. Constitutions of these complexes were confirmed by 1H and 13C NMR spectroscopy and by single-crystal X-ray diffraction analyses. In these reactions the acyl(hydrido)platinum(IV) complexes [Pt(COMe)2Cl(H)(RN=CMeCMe=NR)] (3a, R = n-Pr, 3b, R = Ph) were detected (1H NMR spectroscopy) as intermediates, from which complexes 2a,b were formed by reductive elimination of HCl and MeCHO, respectively. Reactions of the platina-β-diketone la with diazadiene ligands that are unsubstituted at the 2- and 3-positions, RN=CHCH=NR (R = n-Pr, i-Pr, c-Hex, t-Bu), afforded platinum(II) complexes of the type [Pt(COMe)Cl{RN(H)CH=CHN(R)C(O)Me}] (4a, R = n-Pr; 4b, R = i-Pr; 4c, R = c-Hex; 4d, R = t-Bu). All complexes were characterized by NMR spectroscopy (1H, 13C), and the structure of complex 4d was determined by single-crystal X-ray diffraction as well. The organo ligand is formally obtained by 1,4-addition of MeC(O)-H to the diazadiene ligand RN=CHCH=NR. On the basis of DFT calculations of the model complex [Pt(COMe)Cl{MeN(H)CH=CHN(Me)C(O)Me}] (6) and of the (relaxed) free ligand MeN(H)CH=CHN(Me)C(O)Me (7) the electronic structure of complex 6 and the bonding mode of ligand 7 is discussed. DFT calculation of the isomeric acyl(hydrido)platinum(IV) complex [Pt(COMe)2Cl(H)(MeN=CHCH=NMe)] (9a) indicated that it is 18.2 kcal/mol higher in energy than complex 6. Thus, 9a may be an intermediate in the formation of complex 6.
