Comparison of Phosphorus and Silicon:  Hypervalency, Stereochemistry, and Reactivity

Abstract

as Professor of Inorganic Chemistry. His publications number over 200 and include two invited ACS monographs, Nos. 175 and 176, on pentacoordinated phosphorus. His wife, Joan, is a chemist who is a coauthor on many of his publications. Currently, he is Editor-in-Chief of Phosphorus, Sulfur, and Silicon and the Related Elements and Consultant Editor of Main Group Chemistry News.

Nonclassical forces: Seemingly insignificant but a powerful tool to control macromolecular structures

“…[52][53][54][55][56][57] Unlike carbon compounds, organosilicon compounds have the potential to increase their coordination number to 5-and 6-coordinated Si centers and have been characterized by X-ray and nuclear magnetic resonance (NMR) spectroscopy. [58][59][60] Unfortunately, the weak Si/X interactions reported for stabilizing the particular conformations of small molecules in these pseudocoordinations are difficult to characterize by routine spectroscopic methods.…”

New Trends in Hexacoordinated Phosphorus Chemistry

“…This field of phosphorus chemistry was extensively reviewed, most recently by Cavell and Holmes [6][7][8], and only novel structures since 1996 are detailed. A different approach to the generation of neutral P(VI) adducts consists in the generation of dinuclear zwitterionic l -) species.…”

“…In spite of the low conductivity, a rather high cutoff potential of 3.7 V vs Li/Li + was measured. For the lithium salt of tris(oxalato)phosphate anion or [Li,7] much higher specific conductivity (7.0-9.7 mS cm -1 ) was measured in a variety of solvent conditions and the cutoff potential was found to be higher (~4.0 V) [29]. Later, Nanbu investigated the thermal stability and electrolytic properties of tris[4-methyl-1,2-benzenediolato]phosphate or [Li,9] [32].…”

“…Since this discovery, and now for more than 40 years, chemists interested in organic, inorganic, physical, and applied chemistry have generated compounds based on hexacoordinated phosphorus and studied these many derivatives for a variety of applications. Earlier work was reviewed in 1972 by Hellwinkel [5] and more recent articles are those of Cavell [6] and Holmes [7,8]. Several manuscripts or book chapters have also been written on the topic giving a good -yet slightly outdated -overview of the field [9][10][11][12].…”

Preparation And Structure Of Phosphonium Ions With Intramolecular P ← N Coordination; Novel Diphosphonium Salts And Ionomer Containing Backbone Hypervalent Phosphorus

“…Extension of coordination has been widely investigated for phosphoranes [1,2] and silicon compounds [3] but very rarely in the case of phosphanes and phosphonium ions. [4] It has been argued that there is no need to invoke d-orbital participation in the bonding in such hypervalent phosphorus compounds.…”