Calculated properties of cationic phosphorus clusters P2n+1+ with n = 3, 4, 5, and 6

Experimental Evidence for the Existence of Neutral P6: A New Allotrope of Phosphorus

“…In contrast, numerous computational studies on small phosphorus clusters such as hexaphosphabenzene and cubic P 8 have been performed since the 1980s. [1,2] More recent theoretical studies of phosphorus clusters [3] also included ionic species such as cyclic P 5 À , [4] anionic P n À clusters with n 1 ± 9, [5] P (2n1) cations with n 3 ± 5 [6] as well as multiply charged phosphorus species, for example cyclic P 7 3À .…”

“…Electron ionization (EI) of gaseous 1 affords a molecular ion along with Cp*P 6 and Cp* as major fragments. [14] Not surprisingly, loss of one Cp* unit to afford Cp*P 6 prevails in the unimolecular dissociation of the metastable radical cation 1…”

“…[14] Not surprisingly, loss of one Cp* unit to afford Cp*P 6 prevails in the unimolecular dissociation of the metastable radical cation 1…”

“…[16] In the present context, the Cp*P 6 cation is of particular interest. Unimolecular dissociation of the metastable ion Cp*P 6 affords Cp*P 2 and Cp* fragments in a ratio of about 10:1 (Figure 1 a), corresponding to formal losses of P 4 and P 6 , respectively. The latter dissociation gains in importance upon collisional activation (CA) of Cp*P 6 ( Figure 1 b) in that the Cp*P 2 :Cp* ratio decreases to 1.5:1.…”

“…For example, even for the unsubstituted cyclopentadienyl radical, IE(Cp) 8.4 eV is well below IE(P 4 ) 9.1 eV [19] and equals the computed IE(P 6 ) 8.4 eV of the benzvalene structure; [7b] complete methylation is safely assumed to further reduce the IE of the cyclopentadienyl unit. Formation of Cp* as a product of the unimolecular dissociation of Cp*P 6 suggests the interesting perspective that an intact P 6 molecule is lost as a neutral species. However, sequential evaporation of P 4 and P 2 according to 1) Cp*P 6 3Cp*P 2 P 4 and 2) Cp*P 2 3Cp* P 2 cannot be ruled out, and loss of neutral P 2 indeed constitutes a major process in the dissociation of Cp*P 2 .…”