Nitrogen Ligands on Phosphorus(III) Lewis Acceptors: A Versatile New Synthetic Approach to Unusual N−P Structural Arrangements

A series of Lewis acid−base adducts of phosphines with amines or pyridines have been prepared and structurally
characterized, demonstrating the importance of Lewis acceptor behavior in the chemistry of electron-rich (lone-pair-bearing) centers. The neutral and cationic complexes all contain examples of N−P coordinate bonds that are
void of N−P π-bonding and therefore represent definitive N−P single bonds. The structures are examples of N−P
topologies that are rare or have not previously been observed, highlighting the synthetic viability of Lewis acid−base coupling in the still developing field of nitrogen−phosphorus chemistry.