Intramolecular Hydrogen Bonding and Electronic Structure of Thiadiazole Annulated Hemihexaphyrazine

Abstract

Different tautomeric structures of thiadiazole annelated hemihexaphyrazine (TDAHHp hemihexaphyrazine -2,3,5,10,12,13,15,20,22,23,25,30-dodecaazahexaphyrin (C 30 -ченного гемигексафиразина -2,3,5,10,12,13,15,20,22,23,25,30-додекаазагексафирина (C 30 H 15 N 15 S 3

Hemihexaphyrazine and Thiadiazole Annulated Hemihexaphyrazine: A Theoretical Insight into Aromaticity and Energetics of Hydrogen Bonding

“…Relative energies of the most energetically favorable tautomers of HHp demonstrate the similar trend as those previously reported for the TDAHHp molecule. [13] The barriers were calculated by to be very high (more than 50 kJ⋅mol -1 , Figure 2), therefore both HHp and TDAHHp should only adopt the lowest in energy D 3h structures.…”

“…[1][2][3][4][5][6][7] Among a huge number of macrocycles, hemihexaphyrazins of ABABABtype attract a great interest due to their unusually high symmetrical structures, [4][5][6] expanded coordination cavity with enormous potential in coordination chemistry [8][9][10][11] and catalysis, [12] and molecular level information storage. [6] In our recent work [13] a study of tautomeric preference and intramolecular hydrogen bonding was performed for the thiadiazole annulated hemihexaphyrazine (TDAHHp, Scheme 1). According to the results of the DFT calculations, TDAHHp was determined to have the single energetically favourable tautomer of D 3h symmetry, while the other structures were more than 39 kJ·mol -1 higher in energy.…”

Complexes of Ca(II), Ni(II) and Zn(II) with Hemi- and Dicarbahemiporphyrazines: Molecular Structure and Features of Metal-Ligand Bonding

“…[44,45] The concept of aromaticity is widely used in the chemistry of the porphyrazines and their analogues. [46][47][48][49] The nucleus-independent chemical shift (NICS(0)) values calculated at the centers of cyclic fragments demonstrate the conservation of the aromatic properties of benzene fragments belonging to isoindole moieties of hp and dchp complexes and the absence of aromaticity in pyrrole fragments. It should be noted that the oppositely placed benzene moieties in dchp complexes with Ca and Zn are less aromatic as compared to benzene.…”

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

“…Структуры свободных молекул H2hp и H2dchp были определены методом газовой электронографии [19] Строение и энергетика гемигексафиразина, его металлокомплексов и тиадиазол-аннелированного гемигексафиразина Исследование строения молекул гемигексафиразина и его металлокомплексов, а также тиадиазол-аннелированного гемигексафиразина представлено в работах [21][22][23][24][25][26][27][28]. Эффузионным методом Кнудсена с масс-спектрометрическим контролем состава пара определена энтальпия сублимации незамещенного гемигексафиразина, которая составила 252(2) кДж/моль [21].…”

“…Проведенное моделирование электронных спектров на основании результатов расчетов методом TDDFT показало, что оба соединения обладают похожим составом спектра. Q-полосы обоих веществ находятся в области 400 нм, что может быть использовано в оптоэлектронных устройствах чтения и записи информации [23].…”