Nickel(II), copper(I) and zinc(II) complexes supported by a (4-diphenylphosphino)phenanthridine ligand

Abstract

A synthetic route to 4-bromophenanthridine has been devised, enabling the construction of (4-diphenylphosphino)phenanthridine (1), a heterobifunctional Lewis base containing both phosphine and phenanthridine donors. The coordination chemistry of 1 with ions of late first-row transition metals nickel, copper and zinc has been explored, leading to the isolation and characterization of an organometallic Ni(II) complex, chloro(1-naphthyl)[(4diphenylphosphino)phenanthridine]nickel (2), a halide-bridged copper(I) complex, bromo[(4-diphenylphosphino)phenanthridine]copper dimer (3), and a Zn(II) complex, bis(chloro) [(4-diphenylphosphino)phenanthridine]zinc (4). The solid-state structures of 2-4 demonstrate the ability of 1 to support both square planar and tetrahedral geometries. Electrochemical and luminescence studies revealed both metal and ligand-based redox activity and emissive properties.

Phenanthridine-Containing Pincer-like Amido Complexes of Nickel, Palladium, and Platinum

“…than 6-subsituted analogs, due to the electrophilic reactivity of the carbon at this position. Using para-substituted 2-bromo-6-iodo-4-methylaniline, we achieved higher isolated yields (> 90 %) of 4-bromo-2-methylphenanthridine (4-Br) compared with the analogous preparation of 4bromophenanthridine from 2,6-dibromoaniline (isolated yields ~ 35 %), 15 as the iodoarene can be Both L2 and L3 show spectroscopic features diagnostic of phenanthridine groups (Table 1).…”

“…14 We have reported the preparation of (4diphenylphosphino)phenanthridine analogs of (8-diphenylphosphino)quinolines that can be used to form luminescent Cu and Zn coordination compounds. 15 In this work, we present a synthetic route to tridentate phenanthridine-containing ligand frameworks based on bis (8-quinolinyl)amine (L1; Figure 1). 16 Once deprotonated, these compounds (L2, L3) are capable of binding as monoanionic {NNN}amido ligands, 17 and therefore present an opportunity to investigate the coordination chemistry of phenanthridinecontaining 'pincer-type' ligands with divalent Group 10 metal ions.…”

Luminescent Platinum(II) Complexes of N^N–^N Amido Ligands with Benzannulated N-Heterocyclic Donor Arms: Quinolines Offer Unexpectedly Deeper Red Phosphorescence than Phenanthridines

“…6-(Methyl)quinolines amenable for cross-coupling were accessible via the Skraup reaction, 33 while 2methylphenanthridine derivatives were assembled using one-pot Suzuki coupling/condensation reactions. 34 In both cases, methyl substitution improves precursor yields over unsubstituted derivatives. Proligand synthesis proceeded efficiently and the bis(N-heterocyclic)amines L1 and L2 were isolated in high yields (80-90%) as yellow solids following chromatography.…”

Exploiting synergy between ligand design and counterion interactions to boost room temperature phosphorescence from Cu(i) compounds

“…The π--extended P^N donor L3 was synthesized similarly to L1 25 and L2. 26 The tricyclic frame of the phenanthridine moiety was prepared via a one--pot, Pd--catalyzed cross--coupling/condensation of the appropriately substituted aniline with 2-acetylphenylboronic acid (Scheme 1).…”

“…) are all 'head--to--tail', with longer Cu--Cu distances. 25,26 The presence of ortho methyl groups adjacent to the phenanthridine nitrogens thus appears to override the steric preferences of the PPh 2 units to avoid each other in the solid--state. Addition of a second equivalent of the P^N ligand, followed by metathesis with NaPF 6 or NaBPh 4 in tetrahydrofuran, gave bright yellow/green suspensions, from which the targeted [(L) 2 Cu]X salts could be isolated as light yellow solids.…”