TY - JOUR
T1 - Manganese(III) in a pseudo-compressed mixed-donor octahedral environment
T2 - Synthesis, X-ray crystal structure and physicochemical properties
AU - Shongwe, Musa S.
AU - Vandayar, Sandy K.
AU - Fernandes, Manuel A.
AU - Marques, Helder M.
AU - Morris, Michael J.
AU - Heath, Sarah L.
N1 - Funding Information:
We thank the Centre for Molecular Design (School of Chemistry, University of the Witwatersrand), the Foundation for Research Development (South Africa) and DOPSAR (Sultan Qaboos University, Oman) for financial support. We are grateful to Leanne M. Cook (University of the Witwatersrand) for X-ray data collection, Sharon Spey (University of Sheffield) for performing the magnetic susceptibility measurements and Professor Dave Fenton (University of Sheffield) for helpful comments on this work.
PY - 2001/7/15
Y1 - 2001/7/15
N2 - The compound [C5H10NH2][MnL2] [H2L = N-(2-hydroxynaphthalen-l-yl)sarcosine] has been synthesised and characterised using single-crystal X-ray crystallography, spectroscopy and magnetic susceptibility measurements. The crystallographic asymmetric unit displays two similar, independent [MnL2]- complex ions linked via piperidinium cations through hydrogen bonding. The complex ions are alternating and arranged in two non-interacting parallel chains. Each of the complex ions is six-co-ordinate with the donor atoms, provided by the two bifunctional tridentate sarcosinato ligands, being amine nitrogen atoms and carboxylate and naphtholate oxygen atoms. The anionic ligands are co-ordinated facially and are related by a crystallographic centre of inversion at the manganese ion. The mean bond distances Mn-Onaphtholate (1.885 Å), Mn-Ocarboxylate (2.069 Å) and Mn-Namine (2.198 Å) for the two molecules point to a pseudo-compressed octahedral geometry about the Mn(III) ion consistent with a pseudo-Jahn-Teller compression. IR spectroscopy corroborates the unidentate co-ordination fashion of the carboxylate group of the sarcosinato ligand and confirms the presence of the piperidinium cation. The room temperature effective magnetic moment, (8χT)1/2, is indicative of spin-only paramagnetism. As shown by the temperature dependence of the reciprocal of the magnetic susceptibility (χ-1), the magnetic behaviour of [C5H10NH2][MnL2] in the temperature range 5-300 K is in conformity with the Curie-Weiss law, χ = C/(T-θ), with θ = -0.12 K.
AB - The compound [C5H10NH2][MnL2] [H2L = N-(2-hydroxynaphthalen-l-yl)sarcosine] has been synthesised and characterised using single-crystal X-ray crystallography, spectroscopy and magnetic susceptibility measurements. The crystallographic asymmetric unit displays two similar, independent [MnL2]- complex ions linked via piperidinium cations through hydrogen bonding. The complex ions are alternating and arranged in two non-interacting parallel chains. Each of the complex ions is six-co-ordinate with the donor atoms, provided by the two bifunctional tridentate sarcosinato ligands, being amine nitrogen atoms and carboxylate and naphtholate oxygen atoms. The anionic ligands are co-ordinated facially and are related by a crystallographic centre of inversion at the manganese ion. The mean bond distances Mn-Onaphtholate (1.885 Å), Mn-Ocarboxylate (2.069 Å) and Mn-Namine (2.198 Å) for the two molecules point to a pseudo-compressed octahedral geometry about the Mn(III) ion consistent with a pseudo-Jahn-Teller compression. IR spectroscopy corroborates the unidentate co-ordination fashion of the carboxylate group of the sarcosinato ligand and confirms the presence of the piperidinium cation. The room temperature effective magnetic moment, (8χT)1/2, is indicative of spin-only paramagnetism. As shown by the temperature dependence of the reciprocal of the magnetic susceptibility (χ-1), the magnetic behaviour of [C5H10NH2][MnL2] in the temperature range 5-300 K is in conformity with the Curie-Weiss law, χ = C/(T-θ), with θ = -0.12 K.
KW - Jahn-Teller distortion
KW - Magnetic susceptibility
KW - Manganese(III) complex
KW - Spectroscopy
KW - X-ray crystallography
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U2 - 10.1016/S0277-5387(01)00816-6
DO - 10.1016/S0277-5387(01)00816-6
M3 - Article
AN - SCOPUS:0035878713
SN - 0277-5387
VL - 20
SP - 2195
EP - 2201
JO - Polyhedron
JF - Polyhedron
IS - 17
ER -