To Bond or Not to Bond: Metal–Metal Interaction in Heterobimetallic Rare-Earth Metal–Silver Complexes

Abstract

The reaction of 2,4-t Bu 2 -6-(PPh 2 )PhOH (HOAr P ) with silver(I) triflate in a 3:1 molar ratio gave the mononuclear coinage metal complex (HOAr P -κP) 3 Ag I OTf (1). Treatment of HOAr P with Ln III [N(SiMe 3 ) 2 ] 3 (Ln = La, Sm, Y, Yb) in a 3:1 molar ratio yielded the mononuclear rare-earth metal complexes Ln III (OAr P -κ 2 O,P) 3 (2-Ln). The heterobimetallic rare-earth metal−silver complexes Ln III (OTf)(μ-OAr P -1κ 1 O,2κ 1 P) 3 Ag I (3-Ln) were prepared from monometallic precursors by reactions of equimolar amounts of 1 with Ln III [N(SiMe 3 ) 2 ] 3 or 2-Ln with silver(I) triflate, respectively. The compounds were characterized by NMR, ultraviolet−visible (UV−vis), and infrared (IR) spectroscopy, single-crystal X-ray diffraction, elemental analysis, and the effective magnetic moments of the paramagnetic complexes were determined via the Evans NMR method. Computational studies were conducted on 3-La and 3-Y.

Alkyne Cyclotrimerisation, Acyclic Oligomerisation, and Transfer Hydrogenation Catalysed by a Titanium(IV) Phosphinoaryloxide Complex and its Redox Chemistry

“…[13] Recently, phosphinophenolatebased titanium complexes have emerged as valuable catalysts for ethylene dimerization, [14] ethylene and propylene polymerisation, [15] ethylene/norbornene copolymerization, [16,17] and ethylene/hexene copolymerization. [18] Additionally, we recently disclosed heterobimetallic complexes using phosphinophenolate ligands, [19] which prompted us to investigate titanium complexes based on this ligand system further.…”