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Physical Constants of Organic Compounds
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
Cyclohexyl hydroperoxide Cyclohexylideneacetonitrile 2-Cyclohexylidenecyclohexanone Cyclohexyl isocyanate Cyclohexylisopropylamine Cyclohexyl isothiocyanate Cyclohexylmagnesium chloride Cyclohexyl methacrylate Cyclohexylmethylamine Cyclohexyl 2-methylpropanoate 2-Cyclohexylphenol 4-Cyclohexylphenol -Cyclohexyl--phenyl-1piperidinepropanol Cyclohexyl propanoate Cyclohexylsulfamic acid Cyclononane Cyclononanone 1,4-Cyclooctadiene cis,cis-1,5-Cyclooctadiene Cyclooctanamine Cyclooctane Cyclooctanol Cyclooctanone 1,3,5,7-Cyclooctatetraene 1,3,5-Cyclooctatriene cis-Cyclooctene trans-Cyclooctene Cyclooctyne Cyclopamine Cyclopentadecane Trihexphenidyl
Solubility of Conjugated Polymers
Published in Sanjay V. Malhotra, B. L. V. Prasad, Jordi Fraxedas, Molecular Materials, 2017
Crystal A. Young, Andrew C. Jamison, T. Randall Lee
The geometry of a polymer chain is another parameter that can affect solubility. However, modifying the geometry can have significant consequences on the optical properties of the conjugated polymer as well. The simplest conjugated polymer, polyacetylene, is a prime example. As the ratio of cis to trans double bonds increases, the resistivity and the bandgap increase as well; however, neither isomer of polyacetylene is soluble.86 Yet these factors must be considered when altering the geometry of other polymers in an effort to increase polymer solubility. In a study by Anders et al., the cis/trans ratios in the cyclopolymerization of 1,6-heptadiynes were controlled by altering the concentration of the Schrock initiator.87 An all-trans polymer was found to be less soluble than a polymer with a 50/50 ratio of cis to trans in the conjugated chain. Another study involving the ring-opening metathesis polymerization (ROMP) of substituted cyclooctatetraene (COT) produced a mixture of cis and trans along the chain, forming a soluble polyacetylene derivative.88 After isomerizing the chains to an all-trans conformation, the products became insoluble. The authors attribute the decrease in solubility to the less conformationally flexible trans isomer, as compared to the more amorphous cis isomer.89–91 A study of PPV derivatives in OLEDs comments on the solubility of poly(para-phenylene vinylene-alt-3-tert-butyl-meta-phenylene vinylene) synthesized by the Wittig condensation before and after cis/trans isomerization.92 Based on analysis by 1H NMR spectroscopy, the authors estimated that 62% of the alkene bonds had trans configurations before treatment with iodine and full conversion to the trans isomer after treatment. While both isomers are soluble, the authors note the solubility was “noticeably higher” before isomerization. However, in device studies, the trans isomer was found to give higher luminance and efficiency, offering a prime example of the failure of single-parameter optimization for maximizing overall performance.
Stability, optical and charge transport properties of saddle-shaped cyclooctatetrathiophene (COTh) isomers: a theoretical study
Published in Journal of Sulfur Chemistry, 2022
Anuj Tripathi, Vipin Kumar, Prabhakar Chetti
Recent years have witnessed reintroduced interest in the approach to, and synthesis of, cyclic π-conjugated systems that consist of an anti-aromatic ring. Cyclooctatetraene (COT) is one of the conventional π-conjugated flexible molecules with an 8π annulene framework having D2d symmetry containing an integrally nonplanar saddle-shaped geometry. Because of the presence of angle strain and antiaromaticity in COT, it prefers to possess a nonplanar conformation rather than a planar conformation [1–4]. Its planar structural homologues can be obtained by oxidation and reduction reactions, which is a classical example of the influence of Huckel’s rule [5–8]. This was demonstrated by Yamaguchi et. al., who recently reported that the configuration of thiazole fused COT changed from a tub-shape to a planar geometry via reduction and oxidation as predicted by Huckel’s rule [9]. COT-based materials show fascinating behaviors such as cavity control in the size of cage molecules, buckycatchers, electromechanical actuators, organic field-effect transistors (OFETs) and molecular tweezers [10–14].
Inverse coordination metal complexes with oxalate and sulfur, selenium and nitrogen analogues as coordination centers. Topology and systematization
Published in Journal of Coordination Chemistry, 2020
A remarkable number and variety of uranium complexes with oxalato central coordination core have been described, most of them dioxouranium(VI) derivatives. Compounds with fluoro [(µ-C2O4){UO2F2}2]0(187) [338], thiocyanato [(µ-C2O4){UO2 (SCN)3}2]4−(188) [339], nitrato [(µ-C2O4){UO2(NO3)2}2]2+(189), [(µ-C2O4){UO2(NO3)2 (H2O)2}2]2−(190) [340–342] and acetato [(µ-C2O4){UO2(OAc)2}2]2−(191) [343] peripheral groups have been investigated. An organometallic derivative of bis(trimethylsilyl)-cyclooctatetraene (192) [344] is also known (Scheme 55).