Über die Reihenfolge der obersten besetzten Molekülorbitale im Phosphorin‐System

The CH by N Replacement Effects on the Aromaticity and Reactivity of Phosphinines

“…Apart from this observation, we also examined the percentage of s character of lone pairs at P and/or N. As confirmed by experimental observations, a weaker hybridization at phosphorus strongly decreases the basicity of the lone pair. We effectively observe a dramatic difference upon going from nitrogen (%s = 29.1 in 1 ) to phosphorus (%s = 63.8 in 2 ).…”

Phosphaalkene, phospholyl and phosphinine ligands: New tools in coordination chemistry and catalysis

“…Also, in phosphinine (61% of the 3s OA and 39% of the 3p OA) and pyridine (29% of the 2s OA and 71% of the 2p OA) the difference between the respective participation of the ns and np OAs in the lone pairs at the heteroatom is similar to that calculated in the case of HPCH 2 and HNCH 2 (Scheme 2). Another important consequence of this weaker hybridization concerns the basicity of the lone pair which is, as expected, very low in low coordinate phosphorus derivatives [8]. Accurate values of gas-phase proton affinities were obtained from ioncyclotron resonance techniques: 219.4 kcal.mol -1 for C 5 H 5 N and 195.8 kcal.mol -1 for C 5 H 5 P [9].…”

“…In this complex, the HOMO is mainly described by the two π* orbitals on biphosphinines and the contribution of the metal is very small. To the extreme, this complex can be regarded as the coordination of two monoradical anions onto a Ru(0) d 8 center. On the contrary, in tetrahedral complexes, though the HOMO also features an important contribution of the π*orbitals of biphosphinine, the participation of the metal is more important and complexes are closer to real d 10 Recent progresses in the elaboration of synthetic strategies toward functional phosphinines have provided an access to a wide range of sophisticated phosphinines-based ligands and edifices.…”

Core-ionization energies and the anomalous basicity of arsabenzene and phosphabenzene

“…It has been suggested that the phosphorus lone pair may be too diffuse to form a strong bond to a proton. 10 Alternatively it has been argued that the ring structure of phosphabenzene prevents necessary changes in geometry on protonation.5 These two explanations are, however, closely related to one another. In phosphine, for instance, the HPH bond angle is 93°; the corresponding bond hybridization is predominantly p3 with little The P-H bonds must take on more s character and the bond angles shift to the tetrahedral angle (as required also by the symmetry of the PH44" ion).…”