The four coordinate geometric parameter: A new quantification of geometry for four coordinate aluminum and gallium

Abstract

The chemistry of aluminum and gallium compounds has long been a major area of research. Much of this interest stems from the compound's use as Lewis acid catalysts. Efforts to create better aluminum and gallium catalysts have often focused on the addition of new ligands to increase the Lewis acidity of the metals. However, a four coordinate Lewis acid catalyst generally must add a fifth substituent during its catalytic cycle, so the degree to which its geometry encourages this addition will also affect its activity. To help determine the degree to which a four coordinate compound is geometrically optimized to take on a fifth substituent, we have created the four coordinate geometric parameter (FGCP). The FGCP of a compound can be calculated by a simple formula utilizing the ligand-metal-ligand angles of the structure. A high FGCP value indicates a compound with an open space for a fifth substituent, while a lower FGCP value indicates a compound with a more tetrahedral geometry. A negative FGCP suggests a geometry approaching square planar, which is admittedly very unlikely for an aluminum or gallium compound. The FGCP values have been calculated for a number of structures reported in the literature, demonstrating that the method is useful for quantifying the geometry of a variety of known group thirteen compounds.

Structural variation in copper(i) complexes with pyridylmethylamide ligands: structural analysis with a new four-coordinate geometry index, τ4

“…Furthermore, the formulas require multiple steps and, while a simple matter for a computer program to Another formula designed for main group complexes was proposed by Hutchison and coworkers. 36 Their so-called fourcoordinate geometric parameter (FCGP) defines "faces" as the sum of the angles involved in each polytopal face of the fourcoordinate structure. Inserting the largest face value and the sum of the remaining angles into the formula produces the FCGP parameter (eqn (3)).…”

Electrocatalytic property, anticancer activity, and density functional theory calculation of [NiCl(P^N^P)]Cl.EtOH

“…For tetrahedral and square planar geometry, the expected FCGPs are 100 and −40, respectively. [ 70 ] For [Ni(P^N^P)Cl]Cl.EtOH the obtained FCGP parameters is −43, which suggest a distorted square‐planar geometry.…”

“…For tetrahedral and square planar geometry, the expected FCGPs are 100 and −40, respectively. [70] For [Ni(P^N^P) Cl]Cl.EtOH the obtained FCGP parameters is −43, which suggest a distorted square-planar geometry. (30,50,100, and 150 mV s −1 ) reduction peaks could be observed approximately −0.5 V versus NHE, which were subsequently assigned to a Ni II /Ni I couple (Figure 4).…”

Alkali Metallosilicates: Synthesis, Structure and Evaluation in the ROP of ϵ‐Caprolactone

“…In compound 1, each Li atom is bonded to four oxygen atoms (3 × SiÀ O and 1 × O t Bu) with tetrahedral character (THC) [36,37] values for lithium atoms higher than 59 %. Furthermore, the LiÀ OÀ Li bond angles in 1 [90.6(4)°À 102.4(4)°] are consistent with the distorted cubic arrangement (Table 1).…”