Photoelectron spectra of Group 5 compounds. II. Conformational analysis of diphosphine (P2H4)

Abstract

Previous reports of the magnetic behavior of the scheelite phase EuW04 are in conflict. Shafer1 observed paramagnetic behavior down to 1.6 K with 9C = 0 K but few details are

Theoretical study of the dipole-bound anion (HPPH3)−

“…The H 2 PPH 2 tautomer was predicted to adopt the gauche conformation in the gaseous, liquid, and solid phases as demonstrated in infrared ͑IR͒, 11 Raman, 11,13 photoelectron, 12 and phosphorous nuclear magnetic resonance ( 31 P-NMR) 8 investigations. However, the x ray 7 and certain IR and Raman studies 9 on solid diphosphine do not rule out the existence of the staggered form.…”

“…Diphosphine and its tautomer Diphosphine (P 2 H 4 ), known since 1844, is one of the simplest phosphorus compounds 1,2 as reported in the early literature. 3 Although some of its properties have been determined experimentally, [1][2][3][4][5][6][7][8][9][10][11][12][13] and theoretically, [14][15][16][17][18][19][20][21][22][23][24] the tautomer HPPH 3 ͑see Fig. 1͒ has been neither reported experimentally nor studied theoretically up to the mid 1990s, when Rak et al 25 undertook theoretical studies on the structure, stability, and reactivity of P 2 H 4 .…”

Study of Sulfur-Sulfur Nonbonded Interactions in Substituted Diphosphine Disulfides by Gas-Phase UV Photoelectron Spectroscopy

“…In the spectrum of tetramethyldiphosphine disulfides the peaks are assigned, in order of increasing I.E., both by analogy with simpler phosphines and phosphine sulfides and by comparison with CNDO/2 calculations as follows: <7(p-s) at 11.34 eV, (7(p-o at 12.01 eV, cT(c-h) at 14.65 eV (shoulder at 13.9 eV); no bands arising from ionization, expect in the region ca. 10-12 eV (compare [(CH3)2P]2) [16,17], can be identified.…”

“…Several conformers of tetraphenyldiphosphine can exist, like in the case of the tetraalky-diphosphines and diarsines [16,17].…”

“…We have employed ultra violet photoelectron spectroscopy (UPS) in the gas phase, a technique which has proven useful in the study of nonbonded interactions, as in dicarbonyls and tricarbonyls (3)(4)(5)(6)(7)(8)(9), in diazodienes [10], diazobicycloalkenes [11,12], azoderivatives [13,14], and thiocyclohexanes [15], and of conformational equi libria in diphosphines [16][17][18], halomethanes [19], and hydrazines [20].…”