Synthesis and characterization of alkali metal iminophosphoranomethanide complexes.

A variety of group 1 organometallics complexes were synthesized using two iminophosphoranomethanide ligands with differing steric properties. An in-depth structural and spectroscopic analysis was carried out, together with DFT analysis, to probe the nature of the metal-carbon interactions. [Display omitted] Herein we report the synthesis of three sets of alkali metal complexes with the iminophosphoranomethanide ligands {CH(SiMe 3)P(Ph) 2 NSiMe 3 }− (TMSNPC-H) and {CH(SiMe 2 t Bu)P(Ph) 2 NSiMe 3 }− (TBDMSNPC-H), the latter of which is first reported here. The compounds of general formula [M(RNPC-H)] (3-M and 4-M ; M = Li, Na, K) were obtained via a protonolysis reaction between an alkyl reagent (n -butyllithium, benzylsodium, or benzylpotassium) and the proligand. All resulting compounds were characterized by multinuclear NMR, IR spectroscopy, elemental analysis and single crystal X-ray diffraction. We also attempted to prepare the separated ion pairs of [M(TMSNPC-H)] with the matched crown ethers, and obtained the 'ate' complexes [Li(12-crown-4) 2 ]+[Li(TMSNPC-H) 2 ]− (5-Li) and [Na(15-crown-5) 2 ]+[Na(TMSNPC-H) 2 ]− (5-Na), the coordination polymer [{K(18-crown-6) 2 }{K(TMSNPC-H)(18-crown-6)}(TMSNPC-H)] ∞ (6) and separate ion pair complex [K(15-crown-5) 2 ]+[TMSNPC-H]− (7). 5-Li is an unusual lithium-lithiate crown ether species, whilst 5-Na represents the first example of a sodium-sodiate crown-ether complex. [ABSTRACT FROM AUTHOR]