Resorcinol Based Acyclic Dimeric and Cyclic Di- and Tetrameric Cyclodiphosphazanes: Synthesis, Structural Studies, and Transition Metal Complexes

The condensation reaction of resorcinol with cis-[ClP(mu-(NBu)-Bu-t)(2)PN(H)Bu-t] produced a difunctional derivative 1,3-C6H4[OP(mu-(NBu)-Bu-t)(2)PN(H)Bu-t](2) (1), whereas the similar reaction with [ClP(mu-(NBu)-Bu-t)](2) resulted in the formation of a 1:1 mixture of dimeric and tetrameric species, [{P(mu-(NBu)-Bu-t)}(2){1,3-(O)(2)-C6H4}](2) (2a) and [{P(mu-(NBu)-Bu-t)}(2){1,3-(O)(2)-C6H4}](4) (2b), which were separated by repeated fractional crystallization and column chromatography. The reaction of dimer 2a with H2O2 and selenium produces tetrachalcogenides [{(O)P(mu-(NBu)-Bu-t)}(2){1,3-(O)(2)-C6H4}](2) (3) and [{(Se)P(mu-(NBu)-Bu-t)}(2){1,3-(O)(2)-C6H4}](2) (4), respectively. The reaction between the dimer (2a) and [Pd(mu-Cl)(eta(3)-C3H5)](2) or AuCl(SMe2) yielded the corresponding tetranuclear complexes, [{((Cl)(eta(3)-C3H5)Pd)P(mu-(NBu)-Bu-t)}(2){1,3-(O)(2)-C6H4}](2) (5) and [{(ClAu)P(mu-(NBu)-Bu-t)}(2){1,3-(O)(2)-C6H4}](2) (6) in good yield. The complexes 5 and 6 are the rare examples of phosphorus macrocycles containing two or more exocyclic transition metal fragments. Treatment of 1 with copper halides in 1:1 molar ratio resulted in the formation of one-dimensional (1D) coordination polymers, [(CuX){1,3-C6H4{OP(mu-(NBu)-Bu-t)(2)PN(H)Bu-t}}(2)](n) (7, X = Cl; 8, X = Br; 9, X = I), which showed the helical structure in solid state because of intramolecular hydrogen bonding, whereas similar reactions of 1 with 4 equiv of copper halides also produced 1D-coordination polymers, [(Cu2X2)(2){1,3-C6H4{OP(mu-(NBu)-Bu-t)(2)PN(H)Bu-t}(2)}](n) (10, X = Cl; 11, X = Br; 12, X = I), but containing Cu2X2 rhomboids instead of CuX linkers. The crystal structures of 1, 2a, 2b, 4, 7-9, and 12 were established by X-ray diffraction studies.