Intramolecular Hydrogen-Bonded Tertiary Phosphines as 1,3,5-Triaza-7-phosphaadamantane (PTA) Analogues

Abstract

New cationic trialkylphosphines [P(CH(2)NH(2)R){CH(2)N(R)CH(2)N(R)CH(2)}](+) (R = C(6)H(5)CH(2), a; 4-FC(6)H(4)CH(2), b), as their Cl(-) (1a, 1b), SbF(6)(-) (2a, 2b), and PF(6)(-) (3a, 3b) salts, are described. The phosphine framework is conformationally locked, in the solid state, through pairs of intramolecular N-H...N hydrogen bonds which are maintained in the Ru(II) and Rh(III) complexes 4 and 5. Phosphines 1a-3b can be considered as charged variants of the well-known PTA ligand.