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The E1/2 potential associated with reduction of the linearly-functionalized 6,6′-biazulenic scaffold is accurately correlated to the combined σp Hammett parameters of the substituents over >600 mV range. X-ray crystallographic analysis of the 2,2′-dichloro-substituted derivative revealed unexpectedly short C–Cl bond distances, along with other metric changes, suggesting a non-trivial cycloheptafulvalene-like structural contribution. [ABSTRACT FROM AUTHOR]

Research has been conducted on the nitrosyl containing products obtained from aqueous [Ru(bpy)-(NO (sub)2) (sub)4] (super)2- solutions at different pH values. The synthesis, characterization and single-crystal X-ray structure of these products are described.

A three-channel cross-reactive sensor array based on vapoluminescent platinum(II) double salt materials has been characterized. Two arrays were studied, one consisting of [Pt[(CN-cyclododecyl).sub.4]][Pt[(CN).sub.4]] (1), [(phen)Pt[(CN-cyclohexyl).sub.2]][Pt[(CN).sub.4]] (2), and [Pt[(CN-n-tetradecyl).sub.4]][Pt[(CN).sub.4]] (3) materials, where phen = 1,10-phenanthroline, and a second array that has compound 3 replaced by the mixed double salt material [[(phen)Pt[(CN-cyclododecyl)Cl)].sub.2][[(phen)Pt[(CN- cyclododecyl).sub.2]].sub.2][[Pt[(CN).sub.4]].sub.3] (4). Compounds 2, 3 and 4 are characterized here for the first time. Inclusion of solvent vapors into these materials often leads to dramatic shifts in their solid-state absorption and luminescence spectra. In these studies the arrays were exposed to a set of 10 test solvent vapors to determine the ability of each cross-reactive array to give reproducible vapoluminescent spectra characteristic of each solvent vapor. It was discovered that temperature programming between solvent vapor exposures greatly improved the reproducibility of the luminescence spectra obtained. A statistical analysis of three-dimensional resolution factors between pairs of solvent clusters in principal component space supported this assertion. The success of the temperature programming protocol was limited by the thermal stability and the sensitivity to low background water vapor levels of some platinum(II) double salt materials. The ability of the cross-reactive sensor array to differentiate between two different solvent vapors over a large concentration range was also investigated. Acetone and methanol were found to occupy two distinct regions of the three-dimensional principal component space. Detection limits for acetone and methanol were estimated from the principal component analysis as 75 and 6 g/[m.sup.3], respectively.

Research has been conducted on the K (sub)2 [Ru(bpy)(NO (sub)2) (sub)4]. The synthesis of this compound has been carried out via the thermal displacement of benzene by the nitrite ion in the methanol solution and the results are reported.

A metal/ligand cooperative approach to the reduction of small molecules by metal silylene complexes (R2Si=M) is demonstrated, whereby silicon activates the incoming substrate and mediates net two‐electron transformations by one‐electron redox processes at two metal centers. An appropriately tuned cationic pincer cobalt(I) complex, featuring a central silylene donor, reacts with CO2 to afford a bimetallic siloxane, featuring two CoII centers, with liberation of CO; reaction of the silylene complex with ethylene yields a similar bimetallic product with an ethylene bridge. Experimental and computational studies suggest a plausible mechanism proceeding by [2+2] cycloaddition to the silylene complex, which is quite sensitive to the steric environment. The CoII/CoII products are reactive to oxidation and reduction. Taken together, these findings demonstrate a strategy for metal/ligand cooperative small‐molecule activation that is well‐suited to 3d metals. [ABSTRACT FROM AUTHOR]

The electronic and molecular structures for the ground and excited electronic states of aromatic terthiophene (3T), the quinodimethane 3',4'-dibutyl-5,5'-bis(dicyanomethylene)-5,5'-dihydro-2,2':5',2'-terthiophene (3Q), and isologues with the middle ring S-oxidized (3TO2, 3QO2) are analyzed. These have represented the extremes of electron rich and deficient ground states, often displaying complementary properties and the florescence emission is quenched in the sulfonated terthiophene and the contrary effect again would be expected upon sulfonation of a quinoid emitter.

A unique cluster containing two short Pt->Ag dative bonds was synthesized and characterized crystallographically. Two monocationic orthometalated Pt(super II) complexes containing 2-phenylpyridine and the tridentate ligand 9S3 (1,4,7-trithiacyclononane) exhibit axial sulfur interactions with Pt as well as short dative bonds.

The synthesis and characterization of quinodimethane-substituted oligomers is reported. The electrochemistry of these materials indicates their suitability for both p and n biasing in field effect transistors (FETs).

The new compound 1-(2-methoxyphenyl)piperazinium chloranilate (MPP.CA) was synthesized and studied by the single crystal X-ray diffraction method. Its structure was confirmed by infrared spectroscopy. The crystal structure consists of ribbons of chloranilate anions and 1-(2-methoxyphenyl)piperazinium cations linked together by NH…O hydrogen bonds. Two protons are transferred from a chloranilic acid molecule to the nitrogen of the piperazine in this structure. Measurements of AC conductivity as a function of frequency at different temperatures indicated the hopping conduction mechanism; in addition, the variation of dielectric constant as a function ofTconfirmed the transition phase indicated by the differential scanning calorimetry (DSC). The physico-chemical properties, UV-Vis, DSC and dielectric properties are described. Hirshfeld surface analyzes all the intermolecular interactions involved within the structure, which are important to stabilize the structure. [ABSTRACT FROM AUTHOR]