Reference

Dark-Field Oxidative Addition-Based Chemosensing: New Bis-cyclometalated Pt(II) Complexes and Phosphorescent Detection of Cyanogen Halides

Thomas, Samuel W., III; Venkatesan, Koushik; Mueller, Peter; Swager, Timothy M. (Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA). Journal of the American Chemical Society, 128(51), 16641-16648 (English) 2006 American Chemical Society. CODEN: JACSAT. ISSN: 0002-7863. DOCUMENT TYPE: Journal CA Section: 29 (Organometallic and Organometalloidal Compounds) Section cross-reference(s): 75, 79 Heavy metal complexes that are phosphorescent at room temp. are becoming increasingly important in materials chem., principally due to their use in phosphorescent org. light-emitting devices (OLEDs). Their use in optical sensory schemes, however, was not heavily explored.There are some reagents with their cas registry numbers 5315-25-3 and 922726-81-6 are used in this study. Homoleptic bis-cyclometalated Pt(II) complexes are known to undergo oxidative addn. with appropriate electrophiles (principally alkyl halides) by either thermal or photochem. activation. The authors have applied this general reaction scheme to the development of a phosphorescence-based sensing system for cyanogen halides. To carry out structure-property relation studies, previously unreported Pt(II) complexes were prepd. Most of the complexes (excluding those that incorporated substituents on the ligands that forced steric crowding in the square plane) were strongly orange-red phosphorescent (F = 0.2-0.3) in a room-temp. oxygen-free soln. These sterically demanding ligands also accelerated the addn. of cyanogen bromide to these complexes but slowed the addn. of MeI, indicating that the oxidative addn. mechanisms for these two electrophiles is different. The lack of solvent-polarity effect on the addn. of BrCN suggests a radical mechanism. Oxidative addn. of BrCN to the metal complexes in soln. or dispersed in poly(Me methacrylate) gave blue-shifted emissive Pt(IV) complexes. The blue-shifted products give a dark-field sensing scheme that is in sharp contrast to energy transfer-based sensing schemes, which have limited signal-to-noise because of the presence of lower-energy vibronic bands of the energy donor that can overlap with the emission of the acceptor. .

A new ligand containing a pyridine, a 2,2'-bipyridine and a carboxylate moiety and its lanthanide polymeric complexes: Synthesis, characterization and photophysical studies

All Rights Reserved.Some chemicals with cas registry numbers like 1824-81-3 and 5315-25-3 are also used. A new ligand containing a pyridine, a 2,2'-bipyridine and a carboxylate moiety and its lanthanide polymeric complexes: Synthesis, characterization and photophysical studies. Bejan, Claudia C. C.; Demnitz, Friedrich W. J.; de Sa, Gilberto F.; Serra, Osvaldo A.; Menezes, Paulo H.; Junior, Severino A. ( Departamento de Quimica Fundamental, CCEN, Universidade Federal de Pernambuco, Recife, PE 50.670-901, Brazil). Inorganic Chemistry Communications, 9(5), 464-468 (English) 2006 Elsevier B.V. CODEN: ICCOFP. ISSN: 1387-7003. DOCUMENT TYPE: Journal CA Section: 78 (Inorganic Chemicals and Reactions) Section cross-reference(s): 27, 73 The synthesis, characterization and photophys. properties of sol. polymeric complexes obtained from a new ligand (I) and its Eu(III), Tb(III) and Gd(III) ions, is described. The 1H NMR, FTIR, absorption and excitation spectra reveal chelation of the metal with the ligand via a carboxylate and excludes the pyridine moieties coordination. .