Preparation of double decker $\lbrace$Li3(Cl-)(Hhp)$\rbrace$22- dianions and H2TPCor- monoanions by deprotonation of free-base trithiododecaazahexaphyrin (H3Hhp) and triphenylcorrole (H3TPCor) macrocyclesстатьяЭлектронная публикация
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Аннотация:Deprotonation of free-base [30]trithia-2,3,5,10,12,13,15,20,22,23,25,30-dodecaazahexaphyrin (hemihexaphyrazine,H3Hhp) and 5, 10, 15- triphenylcorrole (H3TPCor) macrocycles by an excess of lithiumdiethylamide, LiNEt2, in the presence of three equivalents of cryptand[2.2.2] has been studied.Crystallization of the obtained products after the reaction allows the isolation of crystalline {Cryptand[2.2.2](Li)}2{Li3Cl(Hhp)}2.6C6H4Cl2 (1) and {Cryptand[2.2.2](Li)} {H2TPCor)(-).0.5C6H4Cl2 (2) salts. Compound 1 is the first example of lithium derivative of hemihexaphyrazine which additionally coordinates one Cl(-) anion per three lithium ions. There are five (Li+)...(Cl-) contacts of 2.389(4)-2.456(4) Å length for two independent {Li3Cl(Hhp)} anions. However, one contact elongates to 2.557(4) Å due to shift of Cl(-) anions towards two hydrogen atoms of cryptand[2.2.2] providing the formation of weakhydrogen (Cl(-))...H(cryptand) bonds. Two {Li3Cl(Hhp)} anions are arranged in the double decker {Li3Cl(Hhp)}2(2-) structure due to that the Cl(-) anion of one Li3Cl(Hhp) unit forms additional weak (Li+)...(Cl(-)) contacts of 2.586–2.617(4) Å with two lithium ions of the second {Li3Cl(Hhp)}(-) unit. In contrast to H3Hhp, H3TPCor splits only one hydrogen atom at deprotonation in the same experimental conditions forming a planar H2TPCor(-) anion and, therefore, H3Hhp has higher acidity of central hydrogen atoms in comparison with H3TPCor. Deprotonation preserves diamagnetic state of pristine macrocycles in salts 1 and 2. Their optical properties are also discussed. DFT calculations were carried out for 1 to discuss aromaticity of the macrocycles, electronic structure and optical spectrum of 1.