Dianionic States of Trithiadodecaazahexaphyrin Complexes with Homotrinuclear M^II₃O Clusters (M = Ni and Cu): Crystal Structures, Metal- Or Macrocycle-Centered Reduction, and Doublet–Quartet Transitions in the Dianions

Abstract

Metal complexes of trithiadodecaazahexaphyrin (Hhp) that contain M II 3 O clusters inside a π-extended trianionic (Hhp 3− ) macrocycle have been prepared. Studies of the magnetic properties of Ni II 3 O(Hhp) and Cu II 3 O(Hhp) reveal a diamagnetic and EPR-silent trianionic (Hhp 3− ) macrocycle and diamagnetic Ni II 3 (O 2− ) or paramagnetic Cu II 3 (O 2− ) tetracations. The positive charge of M II 3 O(Hhp) is compensated by one acetate anion {M II 3 O(Hhp)} + (CH 3 CO 2 − ). The three-electron reduction of {M II 3 O(Hhp)} + yields {cryptand 2) crystalline salts. The magnetic properties of 1 reveal the formation of Hhp 5− and the reduction of nickel(II) to the paramagnetic Ni I ion (S = 1/2), which is accompanied by the formation of the {Ni II 2 Ni I O(Hhp 5− )} 2− dianion. As a result, the magnetic moment of 1 is 1.68 μ B in the 20−220 K range, and a broad EPR signal of Ni I was observed. The Hhp 5− macrocycle has a singlet ground state, but the increase in the magnitude of the magnetic moment of 1 above 220 K is attributed to the population of the triplet excited state in Hhp 5− . The {Ni II 2 Ni I O(Hhp 5− )} 2− dianion is transferred from the doublet excited state to the quartet excited state with an energy gap of 1420 ± 50 K. Salt 1 also shows an unusually strong low-energy NIR absorption, which was observed at 1000−2200 nm. In 2, a highly reduced Hhp •6− radical hexaanion (S = 1/2) coexists with a Cu II 3 (O 2− ) cluster (S = 1/2) in the {Cu II 3 O(Hhp •6− )} 2− dianions. The dianions have a triplet ground state with antiferromagnetic exchange between two S = 1/2 spins with J = −6.4 cm −1 . The reduction of Hhp in both salts equalizes the initially alternated C−N bonds, supporting the increase in the Hhp macrocycle electron delocalization.

Synthesis, structure and properties of coordination complexes of tin(ii) phthalocyanine and naphthalocyanine with transition metal fragments

“…Generally, substantial magnetic exchange between two paramagnetic species can yield one signal having an intermediate g -factor value. 17 EPR is not observed for 12 at high temperatures when both paramagnetic species coexist – and Nc˙ 3− . The EPR signal characteristic of is manifested below 60 K when the dimer transfers to the diamagnetic state.…”

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].…”

“…На основании критерия ароматичности NICS установлено, что центральные кольца комплексов {Ni3O(Hhp)} 2и {Cu3O(Hhp)} 2проявляют ароматический характер, в то время как критерий NICS для гемигексафиразина и тиадиазоланнелированного гемигексафиразина показывает отсутствие ароматичности [27].…”

Achievements in the Field of Chemistry of Macroheterocyclic Compounds at the Department of Technology of Fine Organic Synthesis

“…роциклическому лиганду [50]. Таким образом, данные соединения представляют интерес в качестве потенциальных материалов для спинтроники.…”