52614-00-3Relevant academic research and scientific papers
Synthesis and properties of [Pt(4-CO2CH3-py) 2(mnt)]: Comparison of pyridyl and bipyridyl-based dyes for solar cells
Moorcraft, Lucy P.,Morandeira, Ana,Durrant, James R.,Jennings, James R.,Peter, Laurence M.,Parsons, Simon,Turner, Andrew,Yellowlees, Lesley J.,Robertson, Neil
, p. 6940 - 6947 (2008)
The dye complexes [Pt(4-CO2R-py)2(mnt)] (R = H (3a), CH3 (3b)) and the precursor complexes [Pt(4-CO2R-py) 2Cl2] (2a, 2b) (py = pyridyl) were synthesised, characterised by electrochemical, spectroscopic, spectroelectrochemical (UV-vis-nIR and in situ EPR) and hybrid DFT computational methods and attached to a TiO2 substrate to determine charge recombination kinetics. The results were compared to the bipyridyl analogues [Pt{X,X′-(CO 2R)-2,2′-bipyridyl}(mnt)], (X = 3 or 4). The electronic characteristics of the bis-pyridyl complex were found to be different to the bipyridyl complexes making the former harder to reduce, shifting the lowest-energy absorption band to higher energy and showing separate degenerate LUMO orbitals on the two pyridine rings. The latter point determines that the di-reduced pyridyl complex remains EPR active, unlike the bipyridyl analogue. Complex 3a attached to nanocrystalline TiO2 shows a long charge recombination lifetime in comparison with the analogous complex with the ubiquitous 4,4′-(CO2H)2-bipyridyl ligand, suggesting that pyridyl complexes may possess some advantage over bipyridyl complexes in dye-sensitised solar cells.
Novel platinum pyridinehydroxamic acid complexes: Synthesis, characterisation, X-ray crystallographic study and nitric oxide related properties
Griffith, Darren,Bergamo, Alberta,Pin, Sara,Vadori, Marta,Müller-Bunz, Helge,Sava, Gianni,Marmion, Celine J.
, p. 4697 - 4706 (2008/10/09)
Herein, we describe the synthesis and characterisation of a novel class of PtII and PtIV pyridinehydroxamic acid (pyhaH) complexes of general formula cis-[PtIICl2(x-pyhaH)2] and cis-[PtIVCl4(x-pyhaH)2], respectively (where x = 3 or 4) in which the pyridinehydroxamic acid is coordinated to the platinum ion via the pyridine nitrogen only leaving the hydroxamic acid free to potentially release cytotoxic nitric oxide (NO). The crystal structure of the PtIV derivative, cis-[PtCl4(4-pyhaH)2] · 2CH3OH is reported. To establish the biological effect of the uncoordinated hydroxamic acid moiety in the PtII compounds synthesised, the corresponding pyridinecarboxylic acid (pycaH) complexes of general formula cis-[PtIICl2(x-pycaH)2] (where x = 3 or 4) and the PtII pyridine (py) complex, cis-[PtIICl2(py)2] were synthesised and served as reference standards. The NO-releasing properties of each of the PtII compounds, the pyhaH and the pycaH ligands were studied. The PtII pyridinehydroxamic acid derivatives were found to induce potent in vitro effects attributable to either NO-release from the hydroxamic acid moiety and/or stimulation of inducible nitric oxide synthase of endothelial cells.
