Inorganic Chemistry, Vol.37, No.13, 3376-3384, 1998
Ferrimagnetic behavior of multiple phases and solvates of (meso-tetrakis(4-chlorophenyl)porphinato)manganese(III) tetracyanoethenide, [MnTClPP](+)[TCNE](center dot-). Enhancement of magnetic coupling by thermal annealing
(meso-Tetrakis(4-chlorophenyl)porphinato)manganese(II) tetracyanoethenide, [MnTClPP][TCNE], has been prepared and structurally characterized as the toluene and dichloromethane disolvates, and the magnetic and thermal properties of these solvates, as well as their corresponding desolvates, have been determined. The ditoluene solvate (1) has a triclinic unit cell : P (1) over bar, a = 10.171(4) Angstrom, b = 10.189(3) Angstrom, c = 14.522 (3) Angstrom, alpha = 107.51(2)degrees beta = 85.58(2)degrees, gamma = 111.51(3)degrees, Z = 1. The bis(dichloromethane) solvate (2) belongs to the monoclinic unit cell : P2(1)/n, a = 9.894(2) Angstrom, b = 10.697(2) Angstrom, c = 23.560(5) Angstrom, beta = 101.34(2)degrees, Z = 2. The cation is typical with average Mn-N distances of 2.012 Angstrom for both the toluene and dichloromethane solvates. The bonding distances for both planar anions are characteristic of [TCNE](.-). Both solvates have an uniform linear chain (1-D) coordination-polymer structure comprised of alternating cations and anions. Each [TCNE](.-) binds to two Mn-III's in a trans-mu-N-sigma-bound manner with Mn-N spacings of 2.267 (1) and 2.276 Angstrom (2). The Mn-N-C angles are 167.2 and 143.1 degrees, while intrachain Mn Mn separations are 10.189 and 9.894 Angstrom, and the dihedral angle between the MnN4 and [TCNE](.-) mean planes are 86.8 and 52.4 degrees for 1 and 2, respectively. The upsilon(CN) absorptions for the toluene and dichloromethane solvates occur at 2201 m and 2160 s cm(-1) and 2195 m and 2138 s cm(-1), respectively. Upon thermolysis at 175 degrees C 1 desolvates to alpha-[MnTClPP][TCNE] with upsilon(CN) absorptions at 2201 m and 2159 s cm(-1) In contrast, desolvation of 1 in refluxing n-octane leads to beta-[MnTclPP][TCNE] with upsilon(CN) absorptions at 2190 m and 2132 s cm(-1). Upon facile desolvation of 2 to form gamma-[MnTClPP][TCNE] the nitrile absorptions remain essentially unchanged (2195 m and 2137 s cm(-1)). : P (1) over bar, a = 10.171(4) Angstrom, b = 10.189(3) Angstrom, c = 14.522 (3) Angstrom, alpha = 107.51(2)degrees beta = 85.58(2)degrees, gamma = 111.51(3)degrees, Z = 1. The bis(dichloromethane) solvate (2) belongs to the monoclinic unit cell : P2(1)/n, a = 9.894(2) Angstrom, b = 10.697(2) Angstrom, c = 23.560(5) Angstrom, beta = 101.34(2)degrees, Z = 2. The cation is typical with average Mn-N distances of 2.012 Angstrom for both the toluene and dichloromethane solvates. The bonding distances for both planar anions are characteristic of [TCNE](.-). Both solvates have an uniform linear chain (1-D) coordination-polymer structure comprised of alternating cations and anions. Each [TCNE](.-) binds to two Mn-III's in a trans-mu-N-sigma-bound manner with Mn-N spacings of 2.267 (1) and 2.276 Angstrom (2). The Mn-N-C angles are 167.2 and 143.1 degrees, while intrachain Mn Mn separations are 10.189 and 9.894 Angstrom, and the dihedral angle between the MnN4 and [TCNE](.-) mean planes are 86.8 and 52.4 degrees for 1 and 2, respectively. The upsilon(CN) absorptions for the toluene and dichloromethane solvates occur at 2201 m and 2160 s cm(-1) and 2195 m and 2138 s cm(-1), respectively. Upon thermolysis at 175 degrees C 1 desolvates to alpha-[MnTClPP][TCNE] with upsilon(CN) absorptions at 2201 m and 2159 s cm(-1) In contrast, desolvation of 1 in refluxing n-octane leads to beta-[MnTclPP][TCNE] with upsilon(CN) absorptions at 2190 m and 2132 s cm(-1). Upon facile desolvation of 2 to form gamma-[MnTClPP][TCNE] the nitrile absorptions remain essentially unchanged (2195 m and 2137 s cm(-1)).
Keywords:LINEAR-CHAIN;MOLECULAR-STRUCTURE;SPIN ALTERNATION;PORPHYRIN;COMPLEXES;FERROMAGNETS;SYSTEMS;CRYSTAL;IRON