Molecular solids square planar

Xep4 is best prepared by heating a 1 5 volume mixture of Xe and Fi to 400°C under 6 atm pressure in a nickel vessel. It also is a white, crystalline, easily sublimed solid the molecular shape is square planar (Xe-F 195.2pm) and is essentially the same in both the solid and gaseous phases. Its properties are similar to those of XeFi except that it is a rather stronger fluorinating agent, as shown by the reactions ... 

The macrocyclic phthalocyanine ligand will form a complex Pt(phthalocyanine).1106 The crystal structure shows two polymorphs present because of molecular packing.1107 The platinum is in a square planar coordination geometry with a mean Pt—N distance of 1.98 A. The complex can be partially oxidized with iodine to give conducting mixed valence solids.1108 Eighteen fundamental and overtone combination bands are observed in the resonance Raman spectrum of platinum phthalocyanine, and from this data the symmetry of the excited singlets are found to be Dy.. Qlv or D2.1109... 

Tetramine complexes [PdL4]X2 are also common.183 The salts [Pd(NH3)4][PdCl4] and [Pd(NH3)4][PtCl4] have a solid state structure similar to [Pt(NH3)4] [PtCl4], where the square planar molecular units are stacked vertically with short axial metal-metal distances (3.25 A),... 

Bis(salicylaldoximato)nickel(II) is diamagnetic in the solid state, but becomes partially paramagnetic in solution in chloroform157 and aqueous dioxane.151 This is likely to be due to molecular association or solvation,158 rather than to the adoption of a distorted tetrahedral structure in solution.151 The nickel(II) complex readily forms pseudo-octahedral bis-adducts in the presence of large amounts of amines,159 160 although analogous complexes of commercial orffto-hydroxy-oximes have been reported to retain the square-planar structure in hydrocarbon solution in the presence of moderate amounts of ammonia or aliphatic amines.161... 

Work by Paul Beer et al. in Oxford on dithiocarbamate-functionalised resorcarenes has resulted in resorcarene trimers termed molecular loops and molecular tetrahedra composed of four resorcarene units. The molecular loops (pyridine-capped Cd(II) and Zn(II) complexes) can bind C60 which fits neatly into the 16.4 A wide central cavity.35 The slightly larger tetrahedral tetramer which has a 19.4 A edge length, compared to 19.1 A for the loop, is bridged by square planar copper(III) ions, a very unusual oxidation state of copper that is obtained from iodine oxidation of an intermediate copper(II) complex. The solid-state structures of examples of the loop and tetrahedron are shown in Figure 10.35. 

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