231287-70-0Relevant academic research and scientific papers
Synthesis and characterisation of new platinum-acetylide complexes containing diimine ligands
Adams, Christopher J.,James, Stuart L.,Liu, Xiaoming,Raithby, Paul R.,Yellowlees, Lesley J.
, p. 63 - 68 (2007/10/03)
A new class of platinum-bipyridyl compounds has been synthesized by the dehydrohalogenative reaction of [4,4'-bis(tert-butyl)-2,2'-bipyridyl]platinum dihcloride [PtCl2(tBu2bipy)] 1 with terminal alkynes HCCR, in the presence of copper(I) iodide and diisopropylamine. The products [Pt(CCR)2(tBu2bipy)] (R=C6H4NO2-p 2, C6H5 3, C6H4CH3-p 4 or SiMe3 5), have been characterised by spectroscopic and analytical methods, and a single crystal molecular structure determination has been carried out on 4. Extended Hueckel molecular orbital calculations have also been carried out, and the results are used to help rationalise the voltammetric, EPR and spectroelectrochemical properties of the new compounds. These show that compounds 3,4 and 5 undergo a one-electron bipyridyl based redox process, but that 2 has an unresolved two-electron process located on the nitro groups.
Platinum diimine bis(acetylide) complexes: Synthesis, characterization, and luminescence properties
Hissler, Muriel,Connick, William B.,Geiger, David K.,McGarrah, James E.,Lipa, Donald,Lachicotte, Rene J.,Eisenberg, Richard
, p. 447 - 457 (2008/10/08)
A new set of luminescent platinum(II) diimine complexes has been synthesized and characterized. The anionic ligands in these complexes are arylacetylides. The complexes are brightly emissive in fluid solution with relative emission quantum yields φ(em) ranging from 3 x 10-3 to 10-1. Two series of complexes have been investigated. The first has the formula Pt(Rphen)(C≡CC6H5)2 where Rphen is 1,10-phenanthroline substituted in the 5-position with R = H, Me, Cl, Br, NO2, or C≡CC6H5, while the second has the formula Pt(dbbpy)(C≡CC6H4X)2 where dbbpy = 4,4'-di(tert-butyl)bipyridine and X = H, Me, F, or NO2. From NMR, IR, and electronic spectroscopies, all of the complexes are assigned a square planar coordination geometry with cis-alkynyl ligands. The crystal structure of Pt(phen)(C≡CC6H4CH3)2 confirms this assignment. All of the complexes exhibit an absorption band at ca. 400 nm that corresponds to a Pt d → π*(diimine) charge-transfer transition. The variation of λ(max) for this band with substituent variation supports this assignment. From similar changes in the energy of the solution luminescence as a function of substituents R and X, the emissive excited state is also of MLCT origin, but with spin-forbidden character on the basis of excited-state lifetime measurements (0.01-5.6 μs). The complexes undergo electron-transfer quenching, showing good Stern-Volmer behavior using 10-methylphenothiazine and N,N,N',N'-tetramethylbenzidine as reductive quenchers. Excited-state reduction potentials are estimated on the basis of a simple thermochemical analysis. Crystal data for Pt(phen)(C≡CC6H4CH3)2: monoclinic, space group C2/c, a = 19.0961(1) A, b = 10.4498(1) A, c = 11.8124(2) A, β = 108.413(1)°, V = 2236.49 A3, number of reflections 1614, number of variables 150, R1 = 0.0163, wR2 (I > 2σ) = 0.0410.
