[Re(CO)₃Cl(C₅H₄ClP)₂] and [Re(CO)₂Cl(C₅H₄ClP)₃]: synthesis and characterization of two novel rhenium(i) phosphinine complexes

Abstract

Two novel rhenium(I) phosphinine complexes [Re(CO) (2) were synthesized and the molecular structure of both was determined by single crystal X-ray diffraction. In compound 1 the two coordinated phosphinine ligands are arranged in a cis position, whereas compound 2 with three phosphinine ligands crystallizes in a meridional structural motif.Density functional theory investigations were executed to examine the relative stabilities of both complexes 1 and 2.

ReI Complexes of Pyridylphosphinines and 2,2′‐Bipyridine Derivatives: A Comparison

“…The metal precursor [Re(CO) 5 Cl] shows IR bands at ν̃ (CO) = 2155, 2046, 1983 cm –1 . The substitution of two strongly π‐accepting carbonyl ligands by two good π‐acceptor and moderately σ‐donating phosphinines shifts the remaining carbonyl stretching bands significantly towards smaller wavenumbers (ν̃ = 2046, 1992, 1945 cm –1 ), as observed for the only reported phosphinine‐based Re I complex cis ‐[(L) 2 Re(CO) 3 Cl] (L = 2‐chlorophosphinine, see Figure ) . The P ^ N‐based Re I complexes 3 and 4 show carbonyl stretching bands at ν̃ = 2029, 1948, 1937, 1905 (sh), 1880 cm –1 and ν̃ = 2026, 1935, 1899 cm –1 , respectively.…”

“…It turned out that 1 is kinetically much more stable than NIPHOS and, consequently, its coordination chemistry has been exploited by us to quite some extend during the last decade . Surprisingly, we noticed that only two phosphinine complexes of Re I have been reported in literature so far: [Re(CO) 3 Cl(C 5 H 4 ClP) 2 ] and [Re(CO) 2 Cl(C 5 H 4 ClP) 3 ] (Figure ) . As coordination compounds of the type [Re(bpy)(CO) 3 Cl] have attracted considerable interest in the field of photochemical and electrochemical reduction of CO 2 , we now started to investigate the synthesis and characterization of Re I complexes containing the chelating P,N‐hybrid ligand 1 .…”

Overview of the Synthesis and Catalytic Reactivity of Transition Metal Complexes Based on C═P Bond Systems

“…The literature describes complexes of rhenium with a CP bond or complexes supported by a diphosphine ligand − and a few examples of complexes with a phosphaalkene ligand. In the case of manganese, there are several interesting reports that present different types of metal-phosphaalkene ligand coordination.…”