Synthesis, Characterization and Biological Screening of Alkylene Dithiophosphate Derivatives of Macrocyclic Complexes of Pb (II)

Alkylenedithiophosphate derivatives of macrocyclic complexes of Pb (II), having N4S4 potential donors, of the general formula, [Pb(L){S2P(OR)2}2] where L=macrocyclic ligands L1, L2, L3, L4 and L5; R= C2H5-, C3H7n or C3H7i have been synthesized from the reaction of [Pb(L)X2(where X= Clˉ, NO3ˉ or CH3COOˉ) with sodium Alkylenedithiophosphate in 1:2 molar ratios in THF. These complexes have been characterized by elemental analysis, molar conductance, molecular weight determinations, IR, 1H, 13C NMR. Macrocyclic Complexes of Pb (II) derivatives have been studied by screening them Aspergillus flavus, Fusarium oxysporum, Alternaria alternata and bacteria like Salmonella typhi and Bacillus subtili. Alkylenedithiophosphate derivatives were found to be more fungitoxic and antibacterial than their corresponding macrocyclic complexes.

An Efficient Synthesis of [n]Cycloparaphenylenes (n = 9, 12, 15) via the Self-Assembly into Macrocyclic Gold(I)-Oligophenylene Complexes Based on Dynamic Au–C σ-Bonds

The transmetalation of the digold(I) complex [Au2Cl2(Cy2PCH2PCy2)] with oligophenylene diboronic acids gave the triangu-lar macrocyclic complexes [Au2(C6H4)x(Cy2PCH2PCy2)]3 (x = 3, 4, 5) with yields of over 70%. A series of [n]cycloparaphenylenes (n = 9, 12, 15) was isolated in 78–88% yield via the oxidative chlorination of the macrocyclic gold complexes. A kinetics study employing two acyclic dinuclear gold(I) complexes, [Au2R2(Cy2PCH2PCy2)] (R = Ph and/or C6H4-4-F), revealed that an intermolecular Au(I)–C σ-bond-exchange reaction proceeded. These results indicate that the trian-gular complexes were obtained selectively via reversible intermolecular Au(I)–C σ-bond exchanges. By reacting two different oligophenylene diboronic acids with the digold(I) complex, a mixture of macrocyclic complexes incorporating different oli-gophenylene linkers was formed. The oxidative chlorination of this mixture gave [n]cycloparaphenylenes with various num-bers of phenylene units.