TY - JOUR
T1 - Diastereoselectivity in the self-assembly of As2L 2Cl2 macrocycles is directed by the As-π interaction
AU - Cangelosi, Virginia M.
AU - Sather, Aaron C.
AU - Zakharov, Lev N.
AU - Berryman, Orion B.
AU - Johnson, Darren W.
PY - 2007/10/29
Y1 - 2007/10/29
N2 - The As-π interaction, in conjunction with reversible As-thiolate bond formation, is used to direct the self-assembly of dinuclear As2L 2Cl2 (L = a dithiolate) macrocycles that exist as equilibrium mixtures of both syn and anti diastereomers. The diastereomeric excess of these self-assembly reactions is controlled in a predictable manner by prudent choice of different achiral, isomeric ligands. A general method for the preparation of As2L2Cl2 macrocycles is established, and strategies to control the diastereoselective self-assembly of regioisomeric macrocycles in solution and the crystalline state are described. A mechanism for the interconversion between diastereomers (a slow process on the NMR time scale) is suggested, and variable-temperature NMR spectroscopic data show that the diastereomeric excess (de) decreases with increasing temperature. anti-As2(L2,6)2Cl2 crystallizes in monoclinic space group P21/n with a = 6.3949(13), b = 19.675(4), c = 10.967(2) Å, β = 106.817(3)°, and Z = 2. anti-As 2(L1,5)2Cl2 crystallizes in monoclinic space group P21/c with a = 6.813(4), b = 19.085(12), c = 10.277(6) Å, β = 107.788(10)°, and Z = 4. syn-As 2(L1,4)2Cl2·CHCl3 crystallizes in triclinic space group P1 with a = 19.313(4), b = 19.923(4), c = 24.508(5) Å, α = 78.110(4)°, γ = 78.860(5)°, γ = 89.183(5)°, and Z = 12. As2(L1.4)2Cl 2·C6H6 crystallizes in monoclinic space group P21/n with a = 10.3332(7), b = 34.375(2), c = 17.8593(12) Å, β = 98.9650(10)°, and Z = 8.
AB - The As-π interaction, in conjunction with reversible As-thiolate bond formation, is used to direct the self-assembly of dinuclear As2L 2Cl2 (L = a dithiolate) macrocycles that exist as equilibrium mixtures of both syn and anti diastereomers. The diastereomeric excess of these self-assembly reactions is controlled in a predictable manner by prudent choice of different achiral, isomeric ligands. A general method for the preparation of As2L2Cl2 macrocycles is established, and strategies to control the diastereoselective self-assembly of regioisomeric macrocycles in solution and the crystalline state are described. A mechanism for the interconversion between diastereomers (a slow process on the NMR time scale) is suggested, and variable-temperature NMR spectroscopic data show that the diastereomeric excess (de) decreases with increasing temperature. anti-As2(L2,6)2Cl2 crystallizes in monoclinic space group P21/n with a = 6.3949(13), b = 19.675(4), c = 10.967(2) Å, β = 106.817(3)°, and Z = 2. anti-As 2(L1,5)2Cl2 crystallizes in monoclinic space group P21/c with a = 6.813(4), b = 19.085(12), c = 10.277(6) Å, β = 107.788(10)°, and Z = 4. syn-As 2(L1,4)2Cl2·CHCl3 crystallizes in triclinic space group P1 with a = 19.313(4), b = 19.923(4), c = 24.508(5) Å, α = 78.110(4)°, γ = 78.860(5)°, γ = 89.183(5)°, and Z = 12. As2(L1.4)2Cl 2·C6H6 crystallizes in monoclinic space group P21/n with a = 10.3332(7), b = 34.375(2), c = 17.8593(12) Å, β = 98.9650(10)°, and Z = 8.
UR - http://www.scopus.com/inward/record.url?scp=34548513041&partnerID=8YFLogxK
U2 - 10.1021/ic701290h
DO - 10.1021/ic701290h
M3 - Article
AN - SCOPUS:34548513041
SN - 0020-1669
VL - 46
SP - 9278
EP - 9284
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 22
ER -