A New Bond from an Old Molecule:  Formation, Stability, and Structure of P₄H⁺

Abstract

The hitherto unknown gas-phase basicity of the tetraphosphorus molecule, P4, has been determined by means of Fourier transform ion cyclotron resonance mass spectrometry using proton transfer equilibrium techniques. A quantum mechanical treatment of P4 and P4H+ in the framework of the G2 level of theory leads to a proton affinity agreeing nicely with the experimental value and, most important, reveals the existence of a novel kind of chemical bond in P4H+: the symmetrical and essentially covalent (P···H···P) linkage.

On the molecular electron structure of three phosphinine‐containing macrocycles

“…1). This distance is similar to the P-P bond distance obtained both experimentally and theoretically by Cataldo et al by successive one-electron reduction of a macrocycle conformed by two-phosphinines linked by an oxo bridge, 4 and also to those obtained by Abboud et al 13 in cyclic protonated P 4 molecules (P 4 H þ ).…”

Superweak Complexes of Tetrahedral P4 Molecules with the Silver Cation of Weakly Coordinating Anions

“…In contrast to NH 3 , tetrahedral white phosphorus is a very weak base (the proton affinity is only 748 kJ mol À1 ; cf. 847 kJ mol À1 for NH 3 [27] ), and only if the counterion is sufficiently less basic than P 4 a Lewis acid ± base complex is formed. However, as seen for the Li cation above, this electrostatic criterion is not sufficient to allow the isolation of an M (P 4 ) complex when M is a hard univalent metal like lithium.…”

“…COD (0.028 mL, 0.226 mmol) was added to the solution by syringe to give a clear, slightly brownish solution. 1 (63 MHz, CDCl 3 , 258C): d 27.9 (COD), 121.3 (q, 1 J C,F 292.9 Hz; CF 3 ), 127.6 (COD); 31 P NMR (101 MHz, CDCl 3 , 258C): d À 521 (s, P 4 , n 1/2 4 Hz).…”

“…However, knowledge on species containing tetrahedro-P 4 is still very limited. Recently complexes of P 4 with H , [1] Li , [2] or Ag [3] were investigated by mass spectrometry, and on the basis of quantum-chemical investigations it was concluded that the P 4 molecule retains its structural integrity when complexed with Li but forms a P-H-P three-center, two-electron bond in HP 4 . Few structures in which tetrahedral P 4 molecules are coordinated to transition metal fragments are known, [4,5] and the question whether h 2 complexes are derived from neutral tetrahedro-P 4 or from P 4 2À in a tetraphosphabicyclobutane structure is still disputed.…”

Do Organometallic CH4–Me+p Adducts and X4H+ (X = P, As) Clusters Undergo Two-Electron Three-Center Interactions? Some Aspects of Discussion

“…13,14 There should be not enough electrons available for a covalent interaction between carbon atom and the metallic ion for a subsequent bond formation and in this sense these systems may be considered as electron deficient. The second group provides an interesting example for metalloid patterns for chemical interactions 15,16 which as well as first group conforms a set of electron deficient systems. For this reason, these systems offer an encouraging possibility to probe the question for 2e-3c chemical interactions.…”