Theoretical Investigation of Triple Bonding between Transition Metal and Main Group Elements in (η⁵-C₅H₅)(CO)₂M≡ER (M = Cr, Mo, W; E = Si, Ge, Sn, Pb; R = Terphenyl Groups)

Metathetical Exchange between Metal–Metal Triple Bonds

“…These likely correspond to the M–Mo π → π* transitions and have weak lower-energy shoulders probably due to Mo d → π* transitions . The general red-shifting of the absorbances is consistent with a decrease in the MMo bond energy as the group is descended from Ge to Pb …”

“…21 The general red-shifting of the absorbances is consistent with a decrease in the MMo bond energy as the group is descended from Ge to Pb. 27 The infrared spectra of the triple-bonded complexes display two major bands in the CO stretching region with some shoulder features. The bands in 1a appear at 1930 and 1872 cm −1 , while the two bands of 2a, 2b, and 4 are in the ranges 1899−1910 and 1847−1853 cm −1 .…”

“…In each case, the heavy alkylidyne species is thermodynamically favorable due to the formation of strong heterometallic triple bonds (Table S2). The higher bond strengths of the MMo bonds in comparison to those of the homonuclear main group triple bond may be rationalized in terms of the CGMT (Carter, Goddard, Malrieu, and Trinquier) bonding model for their formation. − This model requires a doublet → quartet excitation in the preparation of each main group MAr fragment for bonding.…”

Dispersion-Corrected Relativistic Density Functional Theory (DFT) Calculations of Structure and 119Sn Mössbauer Parameters for M≡SnR Bonding in Filippou’s Stannylidyne Complexes of Molybdenum and Tungsten

“…The values of electron density ρ(0) at the Sn nucleus and 119 Sn isomer shifts (IS) for MSnR bonding in studied stannylidyne complexes are greater (i) for molybdenum complexes than the tungsten complexes, (ii) for six-coordinated complexes than the five-coordinated complexes (except complex 6 ), and (iii) for bidentate dppe ligand than the PMe 3 ligand. On the basis of theoretical studies on structure and bonding analysis of stannylidyne complexes, it has been concluded that, for the relatively stronger MSnR bonding, the electronic population at the Sn atom will be smaller. − Thus, the trends of electron density ρ(0) at the Sn nucleus, as well as the values of 119 Sn isomer shifts (IS) are consistent with the results of structure and bonding energy analysis. The variations of ρ(0) may be correlated with changes in the electronic populations.…”

“…The chemistry of transition-metal carbyne complexes have attracted much as an important class of compounds involving triple bonds between a transition metal and carbyne ligands. − By contrast, the transition-metal complexes of heavier ER (E = Si, Ge, Sn, Pb) ligands has been less flourished. Power and Simons have succeeded in isolating the first stable compound with a MGeR bond, [(η 5 -C 5 H 5 )­(CO) 2 MoGeR] (where R = 2,6-bis­(2,4,6-trimethylphenyl)­phenyl) in 1996. , Since then, a several metal ylidyne complexes are synthesized and spectroscopically as well as structurally characterized. − The theoretical calculations of the MER bonds, to evaluate the nature of transition metal and heavier group 14 ligands interactions have been reported. − …”