title: Radical anion and dianion salts of titanyl macrocycles with acceptor substituents or an extended π-system.
abstract: Crystalline anionic salts of titanyl macrocycles with acceptor substituents or an extended π-system have been obtained for the first time: (PPN+)2{O[double bond, length as m-dash]TiIV(PcCl84-)}2-(1), (PPN+){O[double bond, length as m-dash]TiIV(Nc˙3-)}˙-·2C6H4Cl2(2) and (PPN+)2{O[double bond, length as m-dash]TiIV(AceTPrzPz4-)}2-·1.3C6H4Cl2·0.8C6H5CN (3) where PPN+is the bis(triphenylphosphoranylidene)ammonium cation, PcCl8- 2,3,9,10,16,17,23,24-octachlorophthalocyanine; Nc - 2,3-naphthalocyanine, AceTPrzPz - tetra(acenaphthenopyrazino)porphyrazine. Salts 1-3 were obtained in the reduction of the parent titanyl macrocycles by fluorenone ketyl in the presence of an excess of PPNCl in o-dichlorobenzene with following precipitation of crystals with n-hexane. Reduction of macrocycles in 1-3 is accompanied by the appearance of intense NIR bands in the solid spectra at 963-1159 nm. It has been found that the extended π-system with linear annulation in {O[double bond, length as m-dash]TiIV(Nc˙3-)}˙-provides the shift of the NIR band to smaller energies (1159 nm) in comparison with those in the spectra of {O[double bond, length as m-dash]TiIV(Pc˙3-)}˙-(995-998 nm). Reduction of macrocycles leads also to the alternation of C-Niminebonds due to partial disruption of their aromaticity. The disruption is higher for the dianions in 1 and 3 in comparison with the radical anions in 2. One-dimensional π-π stacking chains and layers are formed in 1 and 3 with diamagnetic {O[double bond, length as m-dash]TiIV(PcCl84-)}2-and {O[double bond, length as m-dash]TiIV(AceTPrzPz4-)}2-dianions, respectively. Salt 2 contains nearly isolated [{O[double bond, length as m-dash]TiIV(Nc˙3-)}˙-]2dimers with a strong π-π interaction between paramagnetic radical anion macrocycles. As a result, a transition from the triplet to singlet state with antiparallel ordering of spins within the dimers is observed in 2 below 200 K.
authors.affiliation: Institute of Problems of Chemical Physics RAS, Chernogolovka, Moscow region 142432, Russia. konarev3@yandex.ru.
authors.forename: Maxim A
authors.identifier: http://orcid.org/0000-0003-0805-601X
authors.initials: MA
authors.lastname: Faraonov
authors.affiliation: Institute of Problems of Chemical Physics RAS, Chernogolovka, Moscow region 142432, Russia. konarev3@yandex.ru.
authors.forename: Dmitri V
authors.identifier: http://orcid.org/0000-0002-7326-8118
authors.initials: DV
authors.lastname: Konarev
authors.affiliation: Institute of Problems of Chemical Physics RAS, Chernogolovka, Moscow region 142432, Russia. konarev3@yandex.ru and Moscow State University, Leninskie Gory, 119991 Moscow, Russia.
authors.forename: Alexey M
authors.initials: AM
authors.lastname: Fatalov
authors.affiliation: Institute of Solid State Physics RAS, Chernogolovka, Moscow region 142432, Russia.
authors.forename: Salavat S
authors.initials: SS
authors.lastname: Khasanov
authors.affiliation: Moscow State University, Leninskie Gory, 119991 Moscow, Russia.
authors.forename: Sergey I
authors.initials: SI
authors.lastname: Troyanov
authors.affiliation: Institute of Problems of Chemical Physics RAS, Chernogolovka, Moscow region 142432, Russia. konarev3@yandex.ru.
authors.forename: Rimma N
authors.initials: RN
authors.lastname: Lyubovskaya