Thermochemistry of Adducts of Bis(2,4-pentanedionato)zinc with Heterocyclic Amines

Abstract

The adducts Zn(AcAc) 2 ‚nL [where L ) piperazine (pipz), morpholine (morph), piperidine (pipd), pyridine (py), 3-methylpyridine ( -pico), 4-methylpyridine (γ-pico), 3-cyanopyridine (3-cyanopy), 4-cyanopyridine (4-cyanopy), 2,2′-bipyridine (bipy), or quinoline (quin); n ) 1 or 3 / 2 ; AcAc ) acetylacetonate] were synthesized and characterized by melting points, elemental analysis, thermal studies, and infrared spectroscopy. From calorimetric studies in solution, the mean standard enthalpies of the zinc-nitrogen bonds were determined.

Thermochemical Parameters of Tetramethylthiourea Adducts of Certain Metal(II) Bromides

“…For the calorimetric study of the complexes, an LKB 8700-1 precision calorimeter was used at the measurements temperature of 298.15 ± 0.02 K. A thin-walled ampoule that contained reactant was broken in a glass reaction vessel filled with (100.00 mL) of calorimetric solvent [29]. The accuracy of the equipment was determined as previously reported [29] [30]. Three to eight replicate measurements were made on each compound and the uncertainty intervals are twice the standard deviations.…”

Thermochemical Parameters of 3-Chloroaniline Complexes of Certain Bivalent Transition Metal Bromides

“…For the calorimetric study of the compounds, an LKB 8700-1 precision calorimeter was used. The temperature of the measurements was 298.15  0.02 K. A thin-walled ampoule that contained reactant was broken in a glass reaction vessel filled with (100.00 mL) of calorimetric solvent [31]. The accuracy of the equipment was determined as previously reported [31,32].…”

“…The temperature of the measurements was 298.15  0.02 K. A thin-walled ampoule that contained reactant was broken in a glass reaction vessel filled with (100.00 mL) of calorimetric solvent [31]. The accuracy of the equipment was determined as previously reported [31,32]. Three to six replicate measurements were made on each compound and the uncertainty intervals are twice the standard deviations.…”

Thermochemistry of 3-Cyanopyridine Adducts of Some Bivalent Transition Metal Bromides

“…The starting material were purified according with methods underlined in the literature. − Table shows the results of these purifications. MBr 2 was synthesized by the reaction of the M(II) carbonates (Strem, 99 %) and hydrobromic acid (Aldrich, 99.999 %).…”