First metallamacrocyclic complexes of Pt(IV) with 3,3,3′,3′- tetraalkyl-1,1′-phenylenedicarbonylbis(thioureas): Synthesis by direct or electrolytic oxidative addition of i2, Br2 and Cl 2
Date
2005
Authors
Westra A.N.
Bourne S.A.
Koch K.R.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Elemental I2 and Br2 cleanly react with the 3 : 3 Pt(II) metallamacrocycle of 3,3,3′,3′-tetra(n-butyl)-1,1′- terephthaloylbis(thiourea) (cis-[PtII3(L p1-S,O)3] 3), in chloroform at room temperature, to yield oxidative addition products; 195Pt NMR studies reveal that a stepwise oxidative addition readily occurs to each of the Pt(II) centres in the metallamacrocycle to yield the mixed valence species cis-[PtII2PtIVI2(Lp1-S,O)3] and cis-[PtIIPtIV2I4(I p1-S,O)3], and the fully oxidised cis-[Pt IV3I6(Lp1-S,O)3] in solution, depending on the mole ratio I2 : 3. Similar results are obtained on treatment of solutions of 3 with elemental Br2. Treatment of the corresponding 2 : 2 Pt(II) complex of 3,3,3′,3′-tetraethyl- 1,1′-isophthaloylbis(thiourea) (cis-[PtII2(L ml-S,O)2] 4) with iodine, results in facile oxidative addition to yield cis-[PtIV2(Lm1-S,O) 2I4] 5, with a trans-Pt(IV)-iodo arrangement. Molecules in the crystal structure of 5 have their trans-Pt(IV)-iodo axes essentially aligned, with very close intermolecular iodide contacts (3.775(1) Å), resulting in chains of weakly bound metallamacrocycles in the solid. An alternative electrolytic synthesis method, using a simple two-compartment glass cell containing 4 and a chosen halide salt in dichloromethane, led to the formation of cis-[PtIV2(Lm1-S,O) 2Br4] 6 and cis-[PtIV2(L m1-S,O)2Cl4] 7, completing characterization of a series of first-reported trans-Pt(IV)-X (X = I, Br, Cl) metallamacrocyclic complexes. © The Royal Society of Chemistry 2005.
Description
Keywords
Bromine, Chlorine, Electrolysis, Glass, Iodine compounds, Nuclear magnetic resonance spectroscopy, Oxidation, Solutions, Synthesis (chemical), Urea, Electrolytic synthesis, Metalloamacrocyclic complexes, Oxidative addition, Platinum compounds
Citation
Dalton Transactions
17
17