What Is The Structure Of 2MBI?

Figure 1 shows the structure of 2MBI, 2MBI-Au, 2MBI-Pd and 2MBI-Ni before and after structure optimization. The drawn 2MBI is presented in Figure 2a and the optimized structure of 2MBI is illustrated in Figure 2b. The most important lengths and angles of bonds for the optimized structure of 2MBI are reported in Table 1. In the optimized structure of 2MBI component, S-H, S-C, C-N bond lengths and the HSC, SCN, CNH, SCN(H) bond angles were 1.386A°, 1.667A°, 1.377A°, 93.291°, 125.921°, 126.521°, 120.142°, respectively. These values agree with experimental and theoretical parameters reported in the literature [66-68] as mentioned inTable1.
The atom of Au as shown in Figure 2c substituted the hydrogen atom, which binds by sulfur in the optimized
Furthermore, the donate electron is given to sulfur atom of the molecule 2MBI this is why after optimization of the structure of the complex 2MBI-Au, gold is still bonded with sulfur of the molecule 2MBI. The frees electrons of gold atom Au(0) and the sulfur atom (S) of the molecule 2MBI can be the origin of the covalent bond. From the work of [71] when —SH is adsorbed to the Au surface; the hydrogen atom is dissociated and the strong Au—S covalent bond is formed subsequently.
The electronic configuration of the palladium Pd(0) is represented by [Kr]4d105s0 [72]. We observe that the latest orbital 5s0 is free of electrons and it can accept two electrons, which can be provided by the free electronic doublet of deprotonated nitrogen atom of 2MBI molecule. This is in order to allow to Pd atom to have the stable configuration as [Kr]4d105s2. This is why after the optimization of the structure of the complex 2MBI-Pd, palladium atom is broken from sulfur and bonded with nitrogen atom of the molecule
According to [73-75] when bifunctional ligands with two donors atoms are used, the gold atom will bind to these ligands through the atom with the higher donor strength according to the sequence Si~P> C > S >Cl> N > O > F. In other words, the two bifunctional are coordinated to gold through the P and S atoms but not N, since P and S are better soft donor than N [76]. Additionally, the gold is often described as a soft metal and therefore, might be expected to prefer soft donor ligands such as sulfur and carbon to the hard donor ligands such as those bonding through nitrogen or oxygen [77]. Consequently, it was generally assumed that gold (I) would not effectively coordinate to a donor nitrogen atom