Two tris(3,5-disubstituted phenyl)phosphines and their isostructural P^V oxides

Abstract

The crystal structures of two bulky tri­aryl­phosphines of emerging inter­est in coordination chemistry and catalysis have been determined, and the syntheses and crystal structures of their corresponding oxides are reported. Each oxide is isostructural to its corresponding phosphine.

Frustrated and Realized Hydrogen Bonding in 4-Hydroxy-3,5-ditertbutylphenylphosphine Derivatives

“…This implies that the phosphine was not 13) and 1.4477(17) Å found for the two sites in 4c″ are significantly depressed from the partial oxygen occupancies and while within the statistical ranges at the 99% confidence level are both in the lower ranges of the lowest quartiles. Results from this study and related work on phosphine oxides with bulky organic substituents 57 seem to indicate that database average P=O lengths may be underestimated from a significant degree of contamination by structures with unrecognized partial oxidation. Classic hydrogen bonds are "realized" in all these phosphine oxide structures (2c, 2c′, 4c, 4c′, and 4c″), while 4c, 4c′, and 4c″ also display partial frustration of H-bonding (details about the intermolecular interactions are described in the following section).…”

“…The crystal structure of 4a (Figures a and S15) is unexpectedly isostructural with that of the parent phosphine 4 with only an increase in unit-cell volume of 4.4% to accommodate the sulfur atom. Isostructural tris- (3,5-dimethylphenyl)-phosphine and its oxide, as well as tris- (4-methoxy-3,5-dimethylphenyl)-phosphine and its oxide, are reported by Hill and Boeré, so that there is precedent for this phenomenon. Phosphine sulfide 4a′ and selenide 4b are isomorphous (Figures b, S16, and S17), also with a 4.4% increase in unit cell volume when Se replaces S; their lattices contain one molecule of xylenes per asymmetric unit.…”

Chemical and Electrochemical Oxidation of Tris(3,5‐di‐tert‐butylphenyl)phosphine – High Z′ Crystal Structures and Conformational Effects Associated with Bulky meta Substituents

“…In support of this notion, the DFT calculations originally used in the data analysis were repeated at the same level of theory but incorporating Grimme's D3 empirical dispersion correction with geometry re‐optimization for 1 – 4 . The results have decreased values of Σ{∠CPC} that correlate directly with the identity of the 3,5‐substituents (Table ) . That is, Σ{∠CPC} > 305° for 3,5‐H 2 , Σ{∠CPC} = 304.8° for 3,5‐diMe (a small change) and 298.3° for 3,5‐di t Bu (a considerably larger contraction).…”

“…We are exploring a series of substituted triarylphosphines 1 – 4 with different donor strengths and hydrophobicity . Whereas 2 – 4 are commercially available, the title phosphine tris(3,5‐di‐ tert ‐butylphenyl)phosphine, 1 , was, at the time our study commenced, only reported in a single communication and remained incompletely characterized .…”

Accurate Crystal Structures of C12H9CN, C12H8(CN)2, and C16H11CN Valence Isomers Using Nonspherical Atomic Scattering Factors

“…The promise of routinely refining H-atom parameters is especially welcome with the increased recognition of the importance of London dispersion interactions (the attractive component of the van der Waals potential) on many aspects of chemical interaction and structure. These are overwhelmingly hydrocarbon interactions, ranging from small molecules, ,− crystal structure directors, chemical reaction mechanisms, and biological macromolecular interaction mechanisms . A dispersion energy donor scale has recently been proposed .…”