Microwave-assisted synthesis and sublimation enthalpies of hemiporphyrazines

Abstract

It was established that microwave irradiation solvent-free processing of 2,6- diaminopyridine or 1,3-phenylenediamine with phthalonitrile or 4-tert-butylphthalonitrile led to corresponding hemiporphyrazines with sufficiently high yields and a huge reduction in the time required for synthesis, from 8–12 h to 20 min. The data of IR and UV-vis spectroscopies and elemental analysis of the final products were found to be similar to those described in literature. The obtained hemiporphyrazines were characterized by 1H and [Formula: see text]C NMR data. We applied the Knudsen effusion method with mass spectrometric control of vapor composition. The mass spectrometric investigations established that the macrocyclic compounds give a stable stream of particles and their enthalpies of sublimation were estimated by the second law of thermodynamics.

Shallow Rate-Overpotential Scaling in Aqueous Molecular Oxygen Reduction Electrocatalysis Across a Family of Iron Macrocycles

“…42 The Fe-N2N′2 group of catalysts is comprised of macrocycles containing mixed pyrrolic/pyridinic ligation to the metal center. [(In2phen)Fe][B(C6F5)4] (5) 43 possesses a cis arrangements of pyrrolic and pyridinic ligation sites, whereas (Py2Carb2)FeCl (6) 44 and(Hp)FeCl (7) 45 both feature a trans disposition of the common N coordination motifs. 7 is also differentiated from 6 by the presence of noncoordinated conjugated N atoms as components of the macrocycle, similar to those found in (Pc)FeCl (3).…”

Microwave-Assisted Synthesis and Characterization of Carba- and Triazolehemiporphyrazines with Camphorapyrazine Fragments

“…Earlier it was established that the reactions of 2,6-diaminopyridine or 1,3-phenylenediamine with phthalonitrile or 4-tert-butylphthalonitrile by microwave irradiation ran under solvent-free protocol with essential reduction in synthesis duration from 8-12 h to 20 min. [25] So, the compounds 5a-c, 6a-c and 7a were obtained by crossover condensation of racemic mixture of 1a, R-(+)-1b or S-(-)-1c-camphoradicyanopyrazine and m-phenylenediamine 2 (at 150 °С for 20 minutes) or 1H-3,5-diamino-1,2,4- The crude products were purified by column chromatography on silica gel using the mixture: CH 2 Cl 2 :MeOH:C 6 H 14 (20:1:6) for 5a-c, CH 2 Cl 2 :MeOH:C 7 H 16 (100:1:6) for 6a-c and CH 2 Cl 2 :MeOH:C 7 H 16 (200: 1: 3) with final purification using gel permeation chromatography (Bio Beads S-X1, chloroform) for 7a and finally recrystallization from ethanol for 5a-c. All products were characterized by massspectrometry, UV-Vis, IR, 1 H and 13 C NMR spectroscopy and elemental analysis data.…”

Vaporization Processes and Accurate Molecular Structure of a Number of Organic and Inorganic Compounds Promising for Use in Technologies Involving the Gas Phase

“…Масс-спектрометрические исследования процессов сублимации соединений гемипорфиразина H2hp, дикарбагемипорфиразина H2dchp и их трет-бутил-замещенных аналогов H2hp-(tBu)2 и H2dchp-(tBu)2 показывают, что данные соедине-ния переходят в газовую фазу конгруэнтно в виде мономерной формы [18]. Энтальпии сублимации H2hp, H2dchp, H2hp-(tBu)2 и H2dchp-(tBu)2 были определены эффузионным методом Кнудсена с масс-спектрометрическим контролем состава пара «по второму закону термодинамики» и составили 191(1), 189(3), 214 (5), 178(4) кДж/моль соответственно [18].…”