Alkali‐Phosphorverbindungen und ihr reaktives Verhalten. XLIII. Zur Leitfähigkeit der Alkali‐diphenylphosphide bzw. ‐arside

Abstract

Alkali‐phosphide und ‐arside des Typs ME(C6H5)2 – M = Li, Na, K, Rb, Cs; E = P. As – sowie KPHC6H5 sind in Dimethylsulfoxid bei 250C und einem Konzentrationsbereich von 2 · 10−3 bis 10 · 10−3 mol/l 1,1‐Elektrolyte. Allgemein zeigen ME(C6H5)2, mit Ausnahme der Lithiumderivate sowie von KPHC6H5 als sehr schwache Elektrolyte, einen Dissoziations‐grad von etwa 0,8. Aus den Meßergebnissen resultiert für die Ionen (C6H5)2P|⊖ bzw. (C6H5)2As|⊖ eine Äquivalentleitfähigkeit von 14.5 bzw. 14,0, Für alkylsubstituierte Alkali‐phosphide MPR2 sind Leitfähigkeitsmessungen in Dimethylsulfoxid infolge solvolytischer Zersetzung nicht durchführbar.

Structure and dynamics of catenated phosphorus(III) dianions

“…23 Conductivity measurements show that these compounds are not completely dissociated into ions even in dimethyl sulfoxide. 24 Initial interpretation of our spectral results in terms of solvent-separated ion pairs was soon abandoned since it provides no natural explanation of the strong temperature dependence of Jaa'. We now feel that the data are best interpreted in terms of equilibria involving coordinate-covalent bonds from anionic phosphorus to K+.…”

Synthesis and molecular structure of the sodium arsanediyl zincate [(thf)Na]2[(EtZn)6(AsSiiPr3)4]

“…The application of sodium dimethylarsanides includes metathesis reactions with halogeno arenes and alkanes; for example, the high reactivity of this nucleophile allowed the synthesis of aryldimethylarsanes from aryl halides [2,3], of (Me 2 AsCH 2 ) 3 C-CH 3 from (ClCH 2 ) 3 C-CH 3 [3] and of Me 2 As-CH = CH-AsMe 2 from 1,2-dichloroethene [4]. The stability of the arsanides strongly depends on the As-bound substituents: Whereas NaAsMe 2 [1][2][3][4] and NaAsPh 2 [5] are stable at room temperature, the trifluoromethyl-substituted arsanides undergo decomposition reactions already above À60°C [6]. Heterobimetallic sodium arsanides have been investigated by Hänisch et al [7] and an anionic cage compound of the constitution of [(thf) 5 Na 4 {(iPr 3 SiAs) 3 (AlH 2 ) 3 } 2 ] 2À was characterized by X-ray structure determination.…”

“…Issleib and coworkers [1] investigated in detail the degree of dissociation of diphenylarsanides in Me 2 SO. The application of sodium dimethylarsanides includes metathesis reactions with halogeno arenes and alkanes; for example, the high reactivity of this nucleophile allowed the synthesis of aryldimethylarsanes from aryl halides [2,3], of (Me 2 AsCH 2 ) 3 C-CH 3 from (ClCH 2 ) 3 C-CH 3 [3] and of Me 2 As-CH = CH-AsMe 2 from 1,2-dichloroethene [4].…”

“…Dec. above 211°C. 1 , 320 parameters, wR 2 = 0.1536 (all data, on F 2 ), R 1 = 0.0608 (observed data), s = 1.12, min. and max.…”