TY - JOUR
T1 - Optically-active tris(O,O′-dialkyl dithiophosphato-S,S′)chromium(III) complexes. Isolation of diastereoisomers and isomerization reactions
AU - Ohta, Hiromi
AU - Kita, Masakazu
AU - Kanno, Hideaki
AU - Kojima, Masaaki
N1 - Funding Information:
This work was supported by a Grant-in-Aid for Scientific Research on Priority Area (No. 1136236 ‘Metal-assembled Complexes’) from the Ministry of Education, Science and Culture, Japan.
PY - 2000/12/22
Y1 - 2000/12/22
N2 - Two optically-active O,O′-dialkyl dithiophosphate ligands, (Bor)2PS2- and (Men)2PS2-, were prepared from P2S5 and the monoterpene alcohols, D-borneol and L-menthol. The chromium(III) complexes, [Cr{(Bor)2PS2}3] and [Cr{(Men)2PS2}3], were prepared by reaction with Cr(NO3)3·9H2O in acetone. The diastereoisomers (Δ and Λ) were separated by fractional crystallization of the complexes from toluene ([Cr{(Bor)2PS2}3]) or acetone ([Cr{(Men)2PS2}3]). The (-)680/CD-Δ-[Cr{(Bor)2 PS2}3] isomer was obtained from the less soluble part. This isomer shows extremely strong CD, Δε (680 nm, toluene) = -15.0 M-1 cm-1. The Δ-[Cr{(Men)2PS2}3] isomer could not be obtained in the optically-pure state, since the complex inverts appreciably during the recrystallization procedure. Activation parameters for isomerization (epimerization), Δ→Λ and Λ→Δ were determined for both complexes, [Cr{(Bor)2PS2}3] and [Cr{(Men)2PS2}3]. [Cr{(Men)2PS2}3] isomerizes much faster than [Cr{(Bor)2PS2}3].
AB - Two optically-active O,O′-dialkyl dithiophosphate ligands, (Bor)2PS2- and (Men)2PS2-, were prepared from P2S5 and the monoterpene alcohols, D-borneol and L-menthol. The chromium(III) complexes, [Cr{(Bor)2PS2}3] and [Cr{(Men)2PS2}3], were prepared by reaction with Cr(NO3)3·9H2O in acetone. The diastereoisomers (Δ and Λ) were separated by fractional crystallization of the complexes from toluene ([Cr{(Bor)2PS2}3]) or acetone ([Cr{(Men)2PS2}3]). The (-)680/CD-Δ-[Cr{(Bor)2 PS2}3] isomer was obtained from the less soluble part. This isomer shows extremely strong CD, Δε (680 nm, toluene) = -15.0 M-1 cm-1. The Δ-[Cr{(Men)2PS2}3] isomer could not be obtained in the optically-pure state, since the complex inverts appreciably during the recrystallization procedure. Activation parameters for isomerization (epimerization), Δ→Λ and Λ→Δ were determined for both complexes, [Cr{(Bor)2PS2}3] and [Cr{(Men)2PS2}3]. [Cr{(Men)2PS2}3] isomerizes much faster than [Cr{(Bor)2PS2}3].
KW - Chromium complexes
KW - Diastereoisomers
KW - Dithiophosphato complexes
KW - Isomerization
KW - Optically-active complexes
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U2 - 10.1016/S0020-1693(00)00307-8
DO - 10.1016/S0020-1693(00)00307-8
M3 - Article
AN - SCOPUS:0034704094
SN - 0020-1693
VL - 311
SP - 75
EP - 79
JO - Inorganica Chimica Acta
JF - Inorganica Chimica Acta
IS - 1-2
ER -