TY - JOUR
T1 - Cyclic and short-chain linear phosphazenes with hindered aryloxy side groups
AU - Allcock, Harry R.
AU - Ngo, Dennis C.
AU - Parvez, Masood
AU - Visscher, Karyn
PY - 1992
Y1 - 1992
N2 - A series of short-chain and cyclic phosphazenes bearing o-dichloro- and o-dimethyl-phenoxy groups have been synthesised, and their structures studied by X-ray crystallography. These compounds are small-molecule models for the corresponding linear high polymers. Structural parameters: N3P3Cl5(OC6H3Cl 2-o) 1, a = 8.081(4), b = 8.074(2), c = 25.868(3) Å, β = 91.11(2)°, space group P21/c, Z = 4; gem-N3P3Cl4(OC6H3Cl 2-o)2 2, a = 18.856(5), b = 8.002(2), c = 16.124(2) Å, β = 114.89(2)°, space group P21/c, Z = 4; N3P3Cl2(OC6H3Cl 2-o)4 4, a = 7.975(3), b = 18.373(4), c = 22.225(3) Å, β = 90.35(2)°, space group P21/n, Z = 4; [NP(OC6H3Cl2-o)2]3 5, a = 12.021(4), b = 19.938(5), c = 18.379(11) Å, β = 90.84(5)°, space group P21/n, Z = 4; gem-N4P4Cl4(OC6H3Cl 2-o)4 6, a = 10.806(2), b = 10.861(2), c = 17.075(7) Å, α = 89.33(4), β = 80.79(3), γ = 68.44(2)°, space group P1, Z = 2; gem-N3P3Cl4(OC6H3Me 2-o)2 7, a = 9.470(3), b = 18.481(12), c = 13.087(8) Å, β = 94.56(4)°, space group P21/n, Z = 4; [NP(OC6H3Me2-o)2]3 8, a = 20.560(5), b = 20.580(9), c = 22.085(4) Å, α = β = γ = 90.0°, space group P4/ncc, Z = 8; OPCl2NP(OC6H3Cl2-o)3 9, a = 14.319(4), b = 16.837(4), c = 20.660(8) Å, space group Pbca, Z = 8; OPCl(OC6H3Me2-o)NPCl(OC6H 3Me2-o)NP(OC6H3Me 2-o)3 10, a = 15.212(3), b = 18.965(1), c = 14.559(2) Å, β = 102.96(2)°, space group P21/c, Z = 4. Despite the bulkiness of the o-dichloro- and o-dimethyl-phenoxy groups, their introduction into the phosphazene structure followed a geminal substitution pathway during the early stages of the reaction. In the reactions with the linear short-chain oligomers these nucleophiles preferentially attacked at the terminal PCl3 rather than at the PCl units in the middle of the chain or those associated with the phosphoryl group. The structure of compound 10 revealed a distorted trans-trans conformation for the PN skeleton, in contrast to the cis-trans arrangement generally believed to exist for linear phosphazene high polymers.
AB - A series of short-chain and cyclic phosphazenes bearing o-dichloro- and o-dimethyl-phenoxy groups have been synthesised, and their structures studied by X-ray crystallography. These compounds are small-molecule models for the corresponding linear high polymers. Structural parameters: N3P3Cl5(OC6H3Cl 2-o) 1, a = 8.081(4), b = 8.074(2), c = 25.868(3) Å, β = 91.11(2)°, space group P21/c, Z = 4; gem-N3P3Cl4(OC6H3Cl 2-o)2 2, a = 18.856(5), b = 8.002(2), c = 16.124(2) Å, β = 114.89(2)°, space group P21/c, Z = 4; N3P3Cl2(OC6H3Cl 2-o)4 4, a = 7.975(3), b = 18.373(4), c = 22.225(3) Å, β = 90.35(2)°, space group P21/n, Z = 4; [NP(OC6H3Cl2-o)2]3 5, a = 12.021(4), b = 19.938(5), c = 18.379(11) Å, β = 90.84(5)°, space group P21/n, Z = 4; gem-N4P4Cl4(OC6H3Cl 2-o)4 6, a = 10.806(2), b = 10.861(2), c = 17.075(7) Å, α = 89.33(4), β = 80.79(3), γ = 68.44(2)°, space group P1, Z = 2; gem-N3P3Cl4(OC6H3Me 2-o)2 7, a = 9.470(3), b = 18.481(12), c = 13.087(8) Å, β = 94.56(4)°, space group P21/n, Z = 4; [NP(OC6H3Me2-o)2]3 8, a = 20.560(5), b = 20.580(9), c = 22.085(4) Å, α = β = γ = 90.0°, space group P4/ncc, Z = 8; OPCl2NP(OC6H3Cl2-o)3 9, a = 14.319(4), b = 16.837(4), c = 20.660(8) Å, space group Pbca, Z = 8; OPCl(OC6H3Me2-o)NPCl(OC6H 3Me2-o)NP(OC6H3Me 2-o)3 10, a = 15.212(3), b = 18.965(1), c = 14.559(2) Å, β = 102.96(2)°, space group P21/c, Z = 4. Despite the bulkiness of the o-dichloro- and o-dimethyl-phenoxy groups, their introduction into the phosphazene structure followed a geminal substitution pathway during the early stages of the reaction. In the reactions with the linear short-chain oligomers these nucleophiles preferentially attacked at the terminal PCl3 rather than at the PCl units in the middle of the chain or those associated with the phosphoryl group. The structure of compound 10 revealed a distorted trans-trans conformation for the PN skeleton, in contrast to the cis-trans arrangement generally believed to exist for linear phosphazene high polymers.
UR - http://www.scopus.com/inward/record.url?scp=37049076832&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=37049076832&partnerID=8YFLogxK
U2 - 10.1039/DT9920001687
DO - 10.1039/DT9920001687
M3 - Article
AN - SCOPUS:37049076832
SN - 1472-7773
SP - 1687
EP - 1699
JO - Journal of the Chemical Society, Dalton Transactions
JF - Journal of the Chemical Society, Dalton Transactions
IS - 10
ER -