A comparison of some properties of C=O and C=S bonds

Abstract

The properties of compounds with carbonyl and thiocarbonyl groups have been examined theoretically, and the results have been compared with the available experimental data. The properties include the bond dissociation energies, the vibrational force constants, the n→π* transitions and the charge distributions. The origin of the differences in properties are discussed

Catalytic Hydrogenation of Thioesters, Thiocarbamates, and Thioamides

“…We then turned our attention to organosulfur compounds containing a typical C=S bond. 20 Three different types of thioamides were tested (entries 4–6). While benzyl thiol and amines were generated as the major products starting from thioamides 5a and 5b , most of thioamide 5c underwent hydrogenative desulfurization to afford the secondary amine 21 in 88% yield.…”

N-Alkyl functionalized barbituric and thiobarbituric acid bithiophene derivatives for vacuum deposited n-channel OFETs

“…19 The terminal C]S bond is comprised of sand p-type molecular orbitals. As the C]S bond length is longer than the C]O bond (1.6 vs. 1.25 Å), 20,21 there is a greater contribution from the s-type HOMO molecular orbital that results in doubly degenerate HOMOs as shown in Table S1. † We nd that the thiobarbituric derivatives are predicted to exhibit 0.2 to 0.4 eV smaller bandgap than their barbituric analogues.…”

Interaction of semicarbazide and thiosemicarbazide pyrene derivatives with anionic and cationic micelles: changed character of pyrene due to alteration in charge density induced by the side chains

“…This minute structural difference may create a huge impact on the properties of the compounds that, in turn, may decide their applications. 16,17 Thus, to get a better idea about the positions of the probes inside the cationic and the anionic micelles, we optimized the structural geometries of PySC and PyTSC and calculated the electron distribution in the HOMO as shown in Fig. 2.…”

“…The oxygen generally has a larger negative charge than sulfur, but the difference decreases as the substituent becomes more electron donating and with NR 2 the charges become equal. 17 We have exploited this extraordinary phenomenon of the CLO and CLS groups in investigating the distribution of two pyrene tagged compounds in cationic and anionic micelles. Steady state fluorescence spectroscopy and anisotropy helped us to come to the conclusion that the general characteristic of pyrene moieties to remain as excimers/dimers can be regulated depending on the induced microheterogeneity by micelles.…”