title: Zwitterionic {Fe(I)Pc(-2)-}·(TMP+) assemblies comprising anionic iron(I) phthalocyanines and coordinating N,N,N'-trimethylpiperazinium cations.
abstract: {[Fe(I)Pc(-2)(-)]·(TMP(+))}·0.5C6H14 (1) and {Co(i)Pc(-2)(-)}·(TMP(+)) (2) salts containing iron(I) and cobalt(I) phthalocyanine anions and N,N,N'-trimethylpiperazinium cations (TMP(+)) have been obtained as single crystals. The TMP(+) cations coordinate to the iron(I) centers in 1 by free nitrogen atoms to form a weak N(TMP(+))-Fe bond of 2.568(3) and 2.553(3) Å length at 150 and 105 K, respectively. This is the first zwitterionic assembly containing anions and cations in one neutral coordination {[Fe(I)Pc(-2)(-)]·(TMP(+))} unit. The Fe(I)Pc(-2)(-) anions manifest strongly asymmetric EPR signals in the spectrum of 1 which can be fitted well by four components at 298 K with g1 = 2.1770, g2 = 2.1681, g3 = 2.1425 and g4 = 2.0708. The signal is attributed to the low-spin (S = 1/2) Fe(I) with the d(7) configuration. The EPR spectrum of 1 does not change qualitatively upon slow cooling from 298 down to 4 K. Quenching of the sample for seconds produces a different EPR spectrum at 4 K. This spectrum can be attributed to the frozen metastable state of Fe(I)Pc(-2)(-) which exists only at low temperatures and transfers to the spectrum observed for the slowly cooled sample above 70 K. Salt 2 contains EPR silent cobalt(I) with the d(8) configuration and in this case the TMP(+) cations do not coordinate to the cobalt(I) atoms.
authors.affiliation: Institute of Problems of Chemical Physics RAS, Chernogolovka, Moscow region, 142432 Russia.
authors.forename: Dmitri V
authors.initials: DV
authors.lastname: Konarev
authors.forename: Alexey V
authors.initials: AV
authors.lastname: Kuzmin
authors.forename: Salavat S
authors.initials: SS
authors.lastname: Khasanov
authors.forename: Rimma N
authors.initials: RN
authors.lastname: Lyubovskaya
mesh_terms: D002412:Cations / Q000737:chemistry; D003035:Cobalt / Q000737:chemistry; D018360:Crystallography, X-Ray; D007211:Indoles / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D054833:Isoindoles; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010879:Piperazines / Q000737:chemistry*
chemical_list: D002412:Cations; D007211:Indoles; D054833:Isoindoles; C585682:N,N,N'-trimethylpiperazinium; D009942:Organometallic Compounds; D010879:Piperazines; D003035:Cobalt; D007501:Iron; C013647:phthalocyanine