TY - JOUR
T1 - Synthesis and resolution of (R*,R*)-(±)-1,1,4,7,10,10-hexaphenyl-1, 10-diarsa-4,7-diphosphadecane
T2 - New ligand for the stereoselective self-assembly of dicopper(I), disilver(I), and digold(I) helicates
AU - Cook, Vernon C.
AU - Willis, Anthony C.
AU - Zank, Johann
AU - Wild, S. Bruce
PY - 2002/4/8
Y1 - 2002/4/8
N2 - Diphenylvinylarsine oxide reacts with 1,2-bis (phenylphosphino)ethane in the presence of potassium tert-butoxide to give the anti-Markovnikov product (R*,R*)-(±)/(R*,R**)- 1,1,4,7,10,10-hexaphenyl-1,10-diarsa-4,7-diphosphadecane dioxide-1AsO,10AsO, which, upon reduction with HSiCl3/NEt3 in boiling acetonitrile, affords in 84% overall yield the di(tertiary arsine)-di(tertiary phosphine) (R*,R*)-(±)/(R*,S*)-diphars. After separation of the diastereomers by fractional crystallization, the (R*,R*)-(±) form of the ligand was resolved by metal complexation with (+)-di(μ-chloro)bis[(R)-1-[1- (dimethylamino)ethyl]-2-phenyl-C2,N]dipalladium(II): (R,R)-diphars, mp 87-88 °C, has [α]D21 = -18.6 (c 1.0, CH2Cl2); (S,S)-diphars has [α]D21 = +18.4 (c 1.0, CH2Cl2). The crystal and molecular structures of the complexes (M)-[M2{(R,R)-diphars}2](PF6)2 (M = Cu, Ag, Au) have been determined: [M-(SCu,SCu)]-(-)- [Cu2{(R,R)-diphars}2]-(PF6)2, orthorhombic, P212121 (No. 19), a = 16.084(3) Å b = 18.376(3) Å, c = 29.149(6) Å, Z = 4; [M-(SAg,SAg)]-(+)- [Ag2{(R,R)-diphars}2](PF6)2, triclinic, P1, a = 12.487(2) Å, b = 12.695(4) Å c = 27.243(4) Å, α= 92.06°, β = 95.19°, γ = 98.23°, Z= 2; [M-(SAu,SAu)]-(-)- [Au2{(R,R)-diphars}2](PF6)2, orthorhombic, P212121 (No. 19), a = 16.199(4) Å, b = 18.373(4) Å, c = 29.347(2) Å, Z = 4. In the copper(I) and gold(I) helicates, each ligand strand completes 1.5 turns of an M helix in a parallel arrangement about the two chiral MAs2P2 stereocenters of S configuration. The unit cell of the silver(I) complex contains one molecule each of the parallel helicate of M configuration and the conformationally related double α-helix of M configuration in which each ligand strand completes 0.5 turns of an M helix about two metal stereocenters of S configuration. Energy minimization calculations of the three structures with use of the program SPARTAN 5.0 gave results that were in close agreement with the core structures observed.
AB - Diphenylvinylarsine oxide reacts with 1,2-bis (phenylphosphino)ethane in the presence of potassium tert-butoxide to give the anti-Markovnikov product (R*,R*)-(±)/(R*,R**)- 1,1,4,7,10,10-hexaphenyl-1,10-diarsa-4,7-diphosphadecane dioxide-1AsO,10AsO, which, upon reduction with HSiCl3/NEt3 in boiling acetonitrile, affords in 84% overall yield the di(tertiary arsine)-di(tertiary phosphine) (R*,R*)-(±)/(R*,S*)-diphars. After separation of the diastereomers by fractional crystallization, the (R*,R*)-(±) form of the ligand was resolved by metal complexation with (+)-di(μ-chloro)bis[(R)-1-[1- (dimethylamino)ethyl]-2-phenyl-C2,N]dipalladium(II): (R,R)-diphars, mp 87-88 °C, has [α]D21 = -18.6 (c 1.0, CH2Cl2); (S,S)-diphars has [α]D21 = +18.4 (c 1.0, CH2Cl2). The crystal and molecular structures of the complexes (M)-[M2{(R,R)-diphars}2](PF6)2 (M = Cu, Ag, Au) have been determined: [M-(SCu,SCu)]-(-)- [Cu2{(R,R)-diphars}2]-(PF6)2, orthorhombic, P212121 (No. 19), a = 16.084(3) Å b = 18.376(3) Å, c = 29.149(6) Å, Z = 4; [M-(SAg,SAg)]-(+)- [Ag2{(R,R)-diphars}2](PF6)2, triclinic, P1, a = 12.487(2) Å, b = 12.695(4) Å c = 27.243(4) Å, α= 92.06°, β = 95.19°, γ = 98.23°, Z= 2; [M-(SAu,SAu)]-(-)- [Au2{(R,R)-diphars}2](PF6)2, orthorhombic, P212121 (No. 19), a = 16.199(4) Å, b = 18.373(4) Å, c = 29.347(2) Å, Z = 4. In the copper(I) and gold(I) helicates, each ligand strand completes 1.5 turns of an M helix in a parallel arrangement about the two chiral MAs2P2 stereocenters of S configuration. The unit cell of the silver(I) complex contains one molecule each of the parallel helicate of M configuration and the conformationally related double α-helix of M configuration in which each ligand strand completes 0.5 turns of an M helix about two metal stereocenters of S configuration. Energy minimization calculations of the three structures with use of the program SPARTAN 5.0 gave results that were in close agreement with the core structures observed.
UR - http://www.scopus.com/inward/record.url?scp=0037041507&partnerID=8YFLogxK
U2 - 10.1021/ic010988d
DO - 10.1021/ic010988d
M3 - Article
SN - 0020-1669
VL - 41
SP - 1897
EP - 1906
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 7
ER -