Different coordination modes of 2-(diphenylphosphino)azobenzenes in complexation with hard and soft metals

Abstract

Control of coordination modes of a ligand in metal complexes is significant because the coordination modes influence catalytic properties of transition metal catalysts. Reactions of 2-diphenylphosphinoazobenzenes, which are in equilibrium with the inner phosphonium salts, with ZnCl(2), W(CO)(5)(THF), and PtCl(2)(cod) gave three different coordination types of metal complexes with distinctive UV-vis absorptions. All the complexes were characterized by X-ray crystallographic analyses. In the zinc and tungsten complexes, the source molecule functions as an amide ligand and a phosphine ligand, respectively. In the platinum complex, the phosphorus molecule works as a tridentate ligand with formation of a carbon-platinum bond.

Heterotridentate Organomonophosphines in Pt(κ3–X1P1X2)(Y) (X1,2 = N1,2 or S1,2), Pt(κ3–P1N1X1)(Y) (X1 = O, C, S or Se) Pt(κ3–P1S1Cl1)(Cl) and Pt(κ3–P1Si1N1)(OL)—Structural Aspects

“…There are two monoclinic complexes [Pt{κ 3 -Ph 2 P 1 (C 7 H 6 N 1 = NCC 1 C 5 H 6 )}(Cl)] (Figure 2) (at 120 K) [20] and [Pt{κ 3 -Ph 2 P 1 (C 7 H 5 N 1 )(C 7 H 8 C 1 )}(py)].BF 4 (at 100 K) [21] (Table 1 (C: Pt(κ 3 -P 1 N 1 C 1 )(Y))). In the former complex, the κ 3 -P 1 N 1 C 1 ligand forms two fivemembered metallocyclic rings of the P 1 C 2 N 1 NCC 1 type, with the values of the chelate rings of 85.2 • (P 1 -Pt-N 1 ) and 78.7 • (N 1 -Pt-C 1 ), respectively.…”

Photoswitchable phosphines in catalysis

“…In this case, the reaction leads to the platinacyclic species C17 by concomitant coordination of phosphorus and nitrogen and metalation of the aryl ring (Scheme 15). [33] The molecular structure of the final product has been ascertained by X-ray diffraction studies. In most instances, in the azobenzene series, coordination does not influence significantly neither the E!Z photoisomerization nor the reverse thermal process.…”

“…In this case, the reaction leads to the platinacyclic species C17 by concomitant coordination of phosphorus and nitrogen and metalation of the aryl ring (Scheme 15). [33] The molecular structure of the final product has been ascertained by X‐ray diffraction studies.…”