102736-04-9Relevant academic research and scientific papers
Reactions of ferrocenyl- and ruthenocenylphosphazenes with lithiometallocenes and the X-ray structures of N3P3F4(η-C5H4) 2Fe, [N3P3F3{(η-C5H4) 2Fe}{(η-C5H4)Fe(η-C5H 5)}], 1,5-N ...
Allcock, Harry R.,Lavin, Karen D.,Riding, Geoffrey H.,Whittle, Robert R.,Parvez, Masood
, p. 1626 - 1635 (2008/10/08)
Full title: Reactions of ferrocenyl- and ruthenocenylphosphazenes with lithiometallocenes and the X-ray structures of N3P3F4(η-C5H4) 2Fe, [N3P3F3{(η-C5H4) 2Fe}{(η-C5H4)Fe(η-C5H 5)}], 1,5-N4P4F6(η-C5H 4)2Fe, and 1,5,3,7-N4P4F4[(η-C5H 4)2Ru]2. Cyclotri- and cyclotetraphosphazenes that bear fluoro and ferrocenyl or ruthenocenyl side groups undergo fluorine replacement with mono- or dilithioferrocene or mono- or dilithioruthenocene or with methyllithium or phenyllithium. The pattern of fluorine replacement is complex and depends on coordination of the incoming organolithium reagent with the skeletal nitrogen atoms and on steric hindrance factors. An unusual double-transannular ruthenocenylphosphazene was isolated from the cyclotetraphosphazene system. Four metallocenylphosphazenes have been studied by X-ray crystallography. Crystals of N3P3F4(η-C5H4) 2Fe (1a) are triclinic, space group P1, with a = 8.074 (1) A?, b = 8.164 (1) A?, c = 11.521 (2) A?, α = 91.37 (2)°, β = 92.31 (2)°, γ = 118.2 (1)°, V = 667.9 A?3, and Z = 2. The structure was refined to discrepancy indices R = 0.038 and Rw = 0.051. The phosphazene ring is severely distorted in response to the presence of the transannular ferrocenyl unit. cis-non-gem-[N3P3F3{(η-C5H 4)2Fe}{(η-C5H4)Fe(η-C 5H5)}] (7) gives orthorhombic crystals, space group P212121, with a = 10.398 (2) A?, b = 10.644 (2) A?, c = 18.769 (2) A?, V = 2077.3 A?3, and Z = 4. The structure was refined to discrepancy indices R = 0.042 and Rw = 0.059. The phosphazene ring is highly distorted in this molecule. The ferrocene transannular tetramer 1,5-N4P4F6(η-C5H 4)2Fe (3a) gives monoclinic crystals, space group P21/n, with a = 8.668 (1) A?, b = 12.823 (1) A?, c = 14.560 (2) A?, β = 100.86 (1)°, V = 1589.3 A?3, and Z = 4. The structure was refined to discrepancy indices R = 0.032 and Rw = 0.041. Even more distortion of the phosphazene ring is found in this molecule. Crystals of the double-transannular phosphazene tetramer 1,5,3,7-N4P4F4{(η-C5H 4)2Ru}2 (10) are monoclinic, space group P21, with a = 7.719 (1) A?, b = 12.151 (5) A?, c = 15.606 (2) A?, β = 101.93 (1)°, V = 1432.1 A?3, and Z = 2. The eight-membered cyclotetraphosphazene ring is severely puckered to adapt to the constraints imposed by the two ruthenocene systems.
