TY - JOUR
T1 - Embracing ligands. Synthesis, characterisation and the correlation between 59Co NMR and ligand field parameters of Co(III) complexes with a new class of nitrogen-thioether multidentate ligand
AU - Sharrad, Clint A.
AU - Cavigliasso, Germán E.
AU - Stranger, Robert
AU - Gahan, Lawrence R.
PY - 2004/3/7
Y1 - 2004/3/7
N2 - The syntheses of the hexadentate ligands 2,2,10,10-tetra(methyleneamine)-4,8-dithiaundecane (PrN4S2amp), 2,2,11,11-tetra(methyleneamine)-4,9-dithiadodecane (BuN4S2amp), and 1,2-bis(4,4-methyleneamine)-2-thiapentyl)benzene (XyN4S2amp) are reported and the complexes [Co(RN4S2amp)]3+ (R = Pr, Bu, Xy) characterised by single crystal X-ray study. The low-temperature (11 K) absorption spectra have been measured in Nafion films. From the observed positions of both spin-allowed 1A1g → 1T1g and 1A1g → 1T2g and spin forbidden 1A1g → 3T1g and 1A1g → 3T2g bands, octahedral ligand-field parameters (10Dq, B and C) have been determined. DFT calculations suggest that significant interaction between the d-d and CT excitations occurs for the complexes. The calculations offer an explanation for the observed deviations from linearity of the relationship between 59Co magnetogyric ratio and β(ΔE)-1 (β = the nephelauxetic ratio; ΔE the energy of the 1A1g → 1T1g transition) for a series of amine and mixed amine/thioether donor complexes.
AB - The syntheses of the hexadentate ligands 2,2,10,10-tetra(methyleneamine)-4,8-dithiaundecane (PrN4S2amp), 2,2,11,11-tetra(methyleneamine)-4,9-dithiadodecane (BuN4S2amp), and 1,2-bis(4,4-methyleneamine)-2-thiapentyl)benzene (XyN4S2amp) are reported and the complexes [Co(RN4S2amp)]3+ (R = Pr, Bu, Xy) characterised by single crystal X-ray study. The low-temperature (11 K) absorption spectra have been measured in Nafion films. From the observed positions of both spin-allowed 1A1g → 1T1g and 1A1g → 1T2g and spin forbidden 1A1g → 3T1g and 1A1g → 3T2g bands, octahedral ligand-field parameters (10Dq, B and C) have been determined. DFT calculations suggest that significant interaction between the d-d and CT excitations occurs for the complexes. The calculations offer an explanation for the observed deviations from linearity of the relationship between 59Co magnetogyric ratio and β(ΔE)-1 (β = the nephelauxetic ratio; ΔE the energy of the 1A1g → 1T1g transition) for a series of amine and mixed amine/thioether donor complexes.
UR - http://www.scopus.com/inward/record.url?scp=1642343656&partnerID=8YFLogxK
U2 - 10.1039/B313189K
DO - 10.1039/B313189K
M3 - Article
SN - 1477-9226
SP - 767
EP - 777
JO - Dalton Transactions
JF - Dalton Transactions
IS - 5
ER -