Computational Design of New N-Heterocyclic Silyl Pincer Fullerenes

Maryam Anafcheh,Mansour Zahedi

doi:10.1007/s12633-021-01168-3

Abstract

A density functional theory study was performed to design new N-heterocyclic silyl pincer fullerenes based on the reactions of diaminofullerene with chlorosilanes SiHRCl2. Reaction energies of the formation of pincer fullerene ligands increased through the substitution of flanking arms with CH3 and phenyl groups. However, substituting hydrogen of SiH2 with methyl slightly increased the corresponding reaction energies; replacing hydrogen with phenyl group decreased the reaction energies of the considered pincer fullerenes. While the calculated electrophilicity values of the pincer fullerenes are larger than the electrophilicity values obtained for the fullerene derivatives, the substitution of hydrogen atoms of central SiH2 and PH2 did not has a noticeable impact on the electrophilicity values of the pincer fullerenes. The only exception was SiHPh(NCH2PH2)2C60. Natural bonding orbital analysis showed that the delocalization of electrons from the lone pairs of phosphorous atoms to the n* orbital of transition metal atoms was a key factor for stabilizing the considered complexes. The strongest interaction was due to the delocalization of electrons from lone pairs of phosphorous atoms in the flanking arms to the LP* of transition metals, which was followed by the delocalization of electrons of the Si-H σ* orbitals to the LP* of transition metals.

Highlights

There has been an extensive growth in the interest in the chemistry of complexes of transition metals of pincer ligands after Moulton and Shaw’s outstanding report in 1976 about a wide range of pincer-ligated metal complexes [1]
Similar data were obtained for the pincer fullerene ligands, which are in agreement with those values obtained for N-Heterocyclic σ-siliyl pincer ligands
The reactions of C60(NH2)2 with chlorosilanes SiHRCl2 (R = H, CH3, and Ph) were taken into account to design the nine pincer fullerene ligands SiHR(NCH2PL2)2C60, R and L = H, CH3, and Ph and the pincer-ligated metal complexes achieved by adding a transition metal to the pincers

Summary

Introduction

There has been an extensive growth in the interest in the chemistry of complexes of transition metals of pincer ligands after Moulton and Shaw’s outstanding report in 1976 about a wide range of pincer-ligated metal complexes [1]. The donor groups don't need to be strongly bonded to make sure that it might reversibly dissociate and form a coordination site needed for activating inert bonds They can react with external ligands (e.g. isocyanides, H2, CO, CO2, dihalides, water, acids, oxidizing and reducing agents, or even Na metal) with the assistance of the thermal stability and tight binding of pincer complexes [8,9,10]. They keep the pincer coordination of the ligand even at raised temperature. The reasonable design and synthesis of pincer-type ligands, of which stereoelectronic properties are controllable using practical modification, have been long an objective in inorganic and organometallic chemistry [12]

Objectives

Results

Conclusion