Reactivity of phosphenium ions toward 1,3- and 1,4-dienes

Abstract

assistance.Registry No. [Co(bpy)2(PN-H)](C104)2, 100229-36-5; [Cu(bpy)-(PN)C1](C104).H20, 100229-39-8. Supplementary Material Available: Listings of thermal parameters, positional parameters of the hydrogen atoms, selected torsion angles and asymmetry parameters, least-squares planes, bond lengths and angles in bpy moieties, and observed and calculated structure factors and packing diagrams (Figures 3 and 4) (48 pages). Ordering information is given on any current masthead page.

Benzothiarsolium cations: evidence for pπ-bonding between arsenic and sulfur in the first structurally characterized arsenium system

“…As for the phosphorus analogs, good yields and ease of isolation of the salts are only possible if the haloarsole is kept at a low concentration with respect to the acid during the reaction to 6~ number of halide ion abstracting agents have been employed and found to react; however, the products have proven difficult to isolate and characterize. (4) 3.637 (2) As--C1(4)' 3.390 (2) S-Cl(4)' 3.583 (2) NH--C1 (3) 2.389 (2) NH--C1(2)' 2.913 (2) prevent aromatic substitution of the benzo moiety by the solvent (5).…”

“…In contrast, systems containing monocoordinate arsenic are extremely rare (41) and dicoordinate arsenic environments are comparatively rare. Imitation of well-established dicoordinate phosphorus systems has provided examples of arsenes (2,42), arsabenzenes (43), polyarsenides (44), and planar polyarsa homocyclic ligands (45). However, aside from the novel complexes (C,Me,),As+ (46) …”

“…While they represent experimentally confirmed contradictions of the "Double Bond R~l e " ,~ a variety of synthetic innovations are responsible for this significant fundamental development, the most common being steric shielding (2). Nevertheless, p.rr bonding is by no means general throughout the p-block, with the restricted valency and coordination of the more electron-rich elements requiring alternative structural or electronic features to support incorporation into a p.rr-bonded system (see, for example, ref.…”

Theoretical evidence for P—S and P—Npπ—pπ bonding within the heterocyclopentadienyl framework

“…It has been reviewed by numerous authors (7)(8)(9). In his review of conlpounds of group 14 and 15 elements involving PIT-PIT multiple bonding, Norman describes how steric protection can be an effective experimental technique to stabilise the bond (9).…”

An unusually large value of1J(31P,31P) for a solid triphenylphosphine phosphadiazonium cationic complex: determination of the sign ofJfrom 2D spin-echo experiments

“…Although the ter couplings cover a wide range, (-)232 Hz to (-)684 Hz, and it has been suggested that 'J(~'P,~'P) in these systems increases (i.e., becomes more negative) with increasing phosphorus-phosphorus bond order (4,5,11).…”