124716-28-5Relevant academic research and scientific papers
Transition-metal derivatives of phosphinophosphazenes: X-ray crystal structures of N3P3Cl4PhPPh2, N3P3Cl4PhPPh2·Cr(CO) 5, and N3P3Cl4PhPPh2·Ru 3(CO)11
Allcock, Harry R.,Manners, Ian,Mang, Michael N.,Parvez, Masood
, p. 522 - 529 (2008/10/08)
The phosphinophosphazene N3P3Cl4PhPPh2 (1) has been synthesized by the reaction of the triethylborane-stabilized phosphazene anion in Li[N3P3Cl4PhBEt3] (4) with PPh2Cl. The arsinophosphazene N3P3Cl4PhAsPh2 (12), the first example of a phosphazene with a P-As bond, was similarly synthesized from 4 and AsPh2Cl. The phosphino group of 1 undergoes facile coordination to low-valent transition-metal fragments; coordination to skeletal nitrogen atoms of the phosphazene ring was not detected. Reaction of 1 with (i) Cr(CO)6 (under ultraviolet irradiation) or Cr(CO)5THF or with (ii) Fe2(CO)9 affords the mononuclear complexes N3P3Cl4PhPPh2·Cr(CO) 5 (5), and N3P3Cl4PhPPh2·Fe(CO) 4 (6), respectively. Heating of 1 with Ru3(CO)12 gives the polynuclear species N3P3Cl4PhPPh2-Ru 3(CO)11 7. The structures of 1, 5, and 7 have been determined by X-ray diffraction. Crystals of 1 are monoclinic, space group P21/c, with a = 18.007 (7) A?, b = 8.447 (3) A?, c = 16.999 (6) A?, β = 116.95 (3)°, V = 2304.8 A?3, and Z = 4. Crystals of 5 are monoclinic, space group P21/c, with a = 17.245 (9) A?, b = 17.901 (2) A?, c = 9.990 (7) A?, β = 93.95 (6)°, V = 3076.6 A?3, and Z = 4. Crystals of 7 are monoclinic, space group P21, with a = 9.498 (6) A?, b = 35.275 (12) A?, c = 13.457 (4) A?, β = 108.05 (3)°, V = 4286.7 A?3, and Z = 4. The P-P bonds of 1, 5, 6, and 7 and the P-As bond of 12 are sources of hydrolytic instability and were shown (in the cases of 1, 6, and 12) to undergo nucleophilic cleavage with sodium trifluoroethoxide. High polymeric phosphazenes bearing backbone-bound phosphino groups have been synthesized in solution but are also hydrolytically sensitive and decompose on attempted isolation.
