Pt‐ and Pd‐Complexes with Acyclic and Heterocyclic P‐Hydroxyaryl‐Substituted N‐Phosphanylmethyl Amino Acids RP(CH₂NHR')₂ and (RPCH₂NR'CH₂)₂ – Evaluation of (P^{^}O)M Chelate Formation

Abstract

P-Hydroxyaryl-and N-C 6 H 4 COOH-substituted phosphanyl-bis(methylamines) and 1,5-diaza-3,7-diphosphacyclooctanes react with M II (cod)Cl 2 (M II = Pt, Pd) to give the corresponding monophosphane L 2 MCl 2 and bisphosphane LMCl 2 complexes. Spontaneous mono-(P^O)M-chelate formation was observed only for L 2 PtCl 2 involving 2-C 6 H 4 OH groups and, partially, on heating the 8-membered LPtCl 2 complex. Addition of excess Et 3 N led to a full conversion to the (P^O)MCl(P^OH) com-[a]

Dynamics and Coordination of a P2N2 Ligand – from Twisted Conformation to Chelation

“…The P‐ and N‐atoms‐bearing heterocycle can be combined with various metals in distinct oxidation states [3] . Research activities have particularly focused on cheap and abundant metals such as Mo, [4] Ni [2a,d,5] or Fe [2d,6] while also complexes with Mn, [2d] Co, [7] Cu, [8] V, [9] Cr, [10] W, [11] Pd, [4a] Au, [12] Ru, [13] Rh [14] or Pt [5a,15] were reported. Respective complexes have served as functional models for metalloenzymes, [5c,16] e. g., hydrogenases, [6a] or were used for the oxidation of alcohols [5d] or ammonia, [17] alkyne hydrofunctionalization, [6b] carbon dioxide activation [14] and dinitrogen reduction [10a] or as blue light emitters [8] .…”

“…A particular advantage of this ligand is the facile variation of the substituents on the four heteroatoms of the P 2 N 2 scaffold [3b,15,24] . Thus, the steric demand of the ligand may be tuned from very low to extremely high and even amino acids can be used for incorporation of the amine functionalities [5b,c,25] .…”