Standard molar enthalpies of formation of zinc(II) β-diketonates and monothio-β-diketonates

Abstract

Keywords: Standard molar enthalpy of formation Enthalpy of dehydration High temperature Calvet microcalorimetry Zinc(II) b-diketonates Zinc(II) monothio-b-diketonates Solution calorimetry Zn(II)-ligand mean molar dissociation enthalpies Bis(dibenzoylmethanate)zinc(II) Bis(thenoyltrifluoroacetonate)zinc(II) Diaquobis (thenoyltrifluoroacetonate) zinc(II) Bis(mono-thiodibenzoylmethanate)zinc(II) Bis[monothiothenoyltrifluoroacetonate] zinc(II) a b s t r a c tThe standard (p = 0.1 MPa) molar enthalpies of formation of crystalline bis(dibenzoylmethanate)zinc(II), Zn(DBM) 2 , diaquobis(thenoyltrifluoroacetonate)zinc(II), Zn(TTFA) 2 (H 2 O) 2 , bis(monothiodibenzoylmethanate)zinc(II), Zn(HDBMS) 2 , and bis(monothio-thenoyltrifluoroacetonate)zinc(II), Zn(HTTFAS) 2 , were determined, at T = 298.15 K, by high precision solution-reaction calorimetry. The standard molar enthalpy of dehydration of the diaquobis(thenoyltrifluoroacetonate)zinc(II), Zn(TTFA) 2 (H 2 O) 2 , complex was measured by high-temperature Calvet microcalorimetry. From the standard molar enthalpies of formation of the complexes in the gaseous state, the mean molar dissociation enthalpies zinc(II)-ligand, hD m i(Zn-L), were derived.kJÁmol À1 Bis(dibenzoylmethanate)zinc(II), Zn(DBM) 2 À546.9 ± 4.0 Diaquobis(thenoyltrifluoroacetonate)zinc(II), Zn(TTFA) 2 (H 2 O) 2 À2556.2 ± 8.4 Bis(monothiodibenzoylmethanate)zinc(II), Zn(DBMS) 2À107.0 ± 5.9 Bis(monothiothenoyltrifluoroacetonate)zinc(II), Zn(TTFAS) 2 À1563.6 ± 8.0

Substituent Effects on the Thermochemistry of Thiophenes. A Theoretical (G3(MP2)//B3LYP and G3) Study

“…Since 2002 our group − in Spain and since 2007 the group of Ribeiro da Silva − in Portugal have published thermochemical studies on thiophenes with a variety of substituents in different positions of the ring. Ribeiro da Silva’s group has also published other studies on thiophenes including complicated substituents, , unrelated to others of interest, and some metal-containing substituents. , Now we have a great body of data on these species, and it is possible to establish correlations between experimental and theoretical data that permit to check the reliability of experimental measurements and also to predict the enthalpies of formation of new thiophenes that are not available in the literature.…”

Synthesis and Crystal Structure Characterization of Zinc (II) Tetronic Acid Complexes

“…The most important and best role of zinc is as a structural cofactor in metalloproteins. Even more, the metal β -diketonates including zinc (II) complexes are a promising class of compounds as inhibitors of HIV-1 and of integrase (IN), since the active site of the enzyme interacts with the metal diketonates [ 12 ]. It is well known that zinc (II) activates essential enzymes such as carboxypeptidase or alcohol dehydrogenase providing a complex with the active site.…”