Boron templated catechol phosphines as bidentate ligands in silver complexes

Reaction of 3-[(diphenylphosphinyl)methyl]benzene-1,2-diol () and 4-[(diphenylphosphinyl)methyl]benzene-1,2-diol () with AgOTf or B(OH)(3) produced the bis-phosphine complexes , , or the borates , , respectively. All products were characterised by analytical and spectroscopic data and single-crystal X-ray diffraction studies. The anionic assembly was shown to act as a template-based chelate ligand toward Ag(+) by forming a neutral complex of composition [()Ag] with AgOTf. Spectroscopic and single-crystal X-ray diffraction studies revealed the presence of a kinetically very stable and conformationally rigid chelate that is best described as a bis-phosphine silver complex with a distinctly non-linear P-Ag-P array and two further secondary Ag-O interactions. Reaction of with AgOTf proceeded in a 2 : 2 molar ratio to give a dimeric product which was, on the basis of spectroscopic data, formulated as a macrocycle of composition [()(2)Ag(2)]. The different molecular sizes of and was underlined by PGSE NMR measurements which gave further evidence for the formation of solvent adducts between the chelate complex and DMF. Analysis of the (1)H,(109)Ag HMQC NMR spectra of provided evidence for a dependence of the (3)J(Ag,H) coupling on torsional angles which resembles a Karplus-type relationship.