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Are phosphatetrahedrane and diphosphatetrahedrane phosphorus or carbon bases?
Author(s) -
Yáñez M.
Publication year - 1998
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/(sici)1099-1395(199808/09)11:8/9<678::aid-poc57>3.0.co;2-j
Subject(s) - protonation , chemistry , carbon fibers , phosphorus , hydrogen bond , computational chemistry , density functional theory , proton , proton affinity , crystallography , molecule , ion , organic chemistry , materials science , composite number , composite material , physics , quantum mechanics
The protonation processes of phosphotetrahedrane (PTH) and diphosphatetrahedrane (DPTH) were studied using density functional theory approaches. The geometries of the neutrals and the protonated species were optimized at the B3LYP/6– 31G(d) level and the final energies were obtained using the B3LYP/6– 311+G(3df,2p) level of theory. Both PTH and DPTH are tetrahedral compounds which behave as carbon bases in the gas phase. In contrast with what was found for other phosphorus‐containing cage structures such as tetraphosphacubane, the nature of the basic center does not change when the hydrogen atoms are substituted by bulky substituents. This is a consequence of the fact that both phosphorus and carbon protonation processes lead to C—P bond fission, so that the repulsive interactions between the susbtituents are not significantly different in carbon‐ or phosphorus‐protonated structures. Protonation of DPTH at the P—P bond yields a local minimum with a P—H—P linkage similar to that described before for the most stable protonated form of P 4 . This seems to indicate that the existence of P—P linkages in strained structures clearly favors the formation of non‐classical protonated species where the proton bridges the two phosphorus atoms. © 1998 John Wiley & Sons, Ltd.