Synthesis of meta-C 6H 4[C(1-pyrazolyl) 2(2-pyridyl)] 2, a fixed geometry bitopic heteroscorpionate and the crystal structure of its unusual square planar silver(I) complex

Abstract

The reaction between bis(1-pyrazolyl)sulfone (prepared in situ by the reaction between NaH, Hpz, and SOCl 2 in THF) and C 6H 4[C(O)(2-py)] 2 in THF catalyzed by CoCl 2 yields m-C 6H 4[C(pz) 2(2-py)] 2 ( 1, pz= pyrazolyl, py=pyridyl) in moderate yield, along with 1-[C(pz) 2(2-py)]-4-[C(O)(2-py)]C 6H 4. The potentially bitopic ligand 1 reacts with AgPF 6 to yield [Ag( 1) 2](PF) 6 ( 3), regardless of the stoichiometry of reagents used in the preparation. X-ray structural analysis of this silver complex shows that two ligands bond to a silver in a κ 2-fashion via the pyrazolyls in one C(pz) 2(py) group in each ligand while the other is non-coordinated. The AgN 4C chelate rings adopt a boat conformation and the silver resides in an unusual square planar coordination environment. Non-covalent forces organize the two-dimensional structure of 3 such that it approaches a layered inorganic–organic hybrid material. Reaction of C 6H 5[C(pz) 2(2-py)] and AgPF 6 yields {Ag(κ 2-C 6H 5[C(pz) 2(2-py)]) 2}(PF 6) ( 4). The structure is disordered but the ligands are bidentate, the nitrogen donor atoms are in a square planar coordination environment about the silver and the overall structure is similar to 3.