Hydrogen bonding in triols on the triphenylphosphine oxide platform in crystal and solution: Effect of linker length

Tripodal Phosphine Oxide Ligand with Tetrazole Functionality

“…1). The bond lengths and angles were typical of the earlier described phosphoryltris(2,1-phenylene)oxyalkenes [27,29,[31][32][33]. Russ.…”

“…The 1 H NMR spectrum of the solution in CDCl 3 revealed the signals of the linker methylene protons as triplets or quintets at 1.6-4.1 ppm. The signals of the phenyl protons of the triphenylphosphine oxide core revealed chemical shifts and multiplicities typical of the related compounds [31] and appeared as doublets and triplets at 6.8-7.7 ppm. The 13 C NMR spectrum contained the singlet signals of the linker methylene groups at 13-66 ppm and the CN group signals at 119.3 ppm.…”

“…The O 1 P 1 C 22 O 4 angle corresponding to the substituent located oppositely to the phosphine oxide group equaled -172.2(1)°, two other substituents forming the OPCO angles of 38.6(1) to 64.8(1)°. In the earlier described cases of tris(tetrazoles) and tris(alkanols) [31], the molecule conformation has been additionally stabilized by two C-H•••O(P) bonds. Molecule of compound 4 also contained two O-H•••O(P) intramolecular bonds formed by the substituents which were to the same side as the P=O group (Fig.…”

“…The chemical shifts in the 31 P NMR spectra were determined relative to 85% H 3 PO 4 as external reference. The signals were assigned by comparison with the spectra of similar compounds [31]. Melting points were determined in a melting point apparatus using short Anschutz thermometers.…”

A multi-responsive system based on intramolecular B ← OP Lewis acid–base pairs

“…The emission intensity enhancement may be caused by both aggregation induced structural rigidification 32 and restoration of ICT (NMe 2 → B). Upon water addition, the hydrogen atoms of water molecules likely interact with the phosphine oxide groups in B2 to form intermolecular hydrogen bonds, 33 leading to a gradual decrease of the nucleophilicity of the oxygen atom on the biarylphosphine oxide fragment, and consequently reducing the strength of the intramolecular B ← O bond. This hypothesis can be proved by the 11 B NMR analyses, which showed that the 11 B peak shifts from 14.20 ppm in THF to 20.50 ppm in the 3 : 7 solvent mixture of THF and water (Fig.…”