Supramolecular assemblies antimony

The coordination geometry around antimony is pentagonal bipyramidal, with a benzene molecule occupying one axial site another axial site is occupied by a chlorine atom bonded to antimony by a primary Sb-Cl bond. In the equatorial plane there are two primary (normal covalent) Sb-Cl bonds (in the range 2.340-2.378 A) whereas three other secondary Sb- -Q interactions (range 3.401-4.04 A) distort the geometry and contribute to the formation of the supramolecular architecture. The supramolecular assembly exists only in the solid state in solution or melt disassembly occurs. 

Some antimony and bismuth xanthates tend to self-assemble through M - -S secondary bonds into supramolecular structures. 

The structural chemistry of some metal dithiocarbamates, i.e. systematics, coordination modes, crystal packing, and supramolecular self-assembly patterns of nickel, zinc, cadmium, mercury,363 organotin,364 and tellurium,365 366 complexes has been thoroughly analyzed and discussed in detail. Supramolecular self-assembly frequently occurs in non-transition heavier soft metal dithiocarbamates. Thus, lead(II),367 bismuth(III)368 zinc,369 cadmium,370 and (organo)mercury371 dithiocarbamates are associated through M- S secondary bonds, to form either dimeric supermolecules or chain-like supramolecular arrays. The arsenic(III)372 and antimony(III)373 dithiocarbamates are... 

The sum of the covalent radii for antimony, i.e. the expected Sb-Sb primary bond length, is 2.74 A, and the sum of van der Waals radii is Sb---Sb 4.10 A. If experimental data are compared with these values several supramolecular self-assembled distibanes can be identified. 

---