Syntheses, Structures, and Properties of Biphosphinines Tethered Aromatic π-System

Abstract

The syntheses of a series of biphosphinine derivatives inserted an aromatic π-spacer have been achieved. Their absorption, emission properties, and electrochemical behavior are also disclosed.

Buchwald–Hartwig Amination of Phosphinines and the Effect of Amine Substituents on Optoelectronic Properties of the Resulting Coupling Products

“…The 13 C NMR spectra of 2a – r display signals at low field (171.3–171.8 ppm), where 51–53 Hz of J CP couplings are also exhibited, which were assigned to the carbon atoms at the 2,6-positions of the phosphinine ring. In the 31 P NMR spectra, the signals for the low-coordinate phosphorus atom in the phosphinine ring of 2a – r appear in the range of 174.3–180.1 ppm, which is consistent with previously reported values for aryl-substituted phosphinines …”

Over one century after discovery: pyrylium salt chemistry emerging as a powerful approach for the construction of complex macrocycles and metallo-supramolecules

“…For instance, pyridine ring can be achieved by reacting ammonia gas with pyrylium salts without modifying the structures. 114 Using this strategy, other nucleophiles are able to convert the pyrylium ring into a series of heterocycles such as pyridines 34 , phosphinines [35][36][37] , pyridinium salts 38,39 , thiopyrylium salts 40 and betaine dyes 41,42 , in order to introduce a variety of functions and applications. Moreover, the stability of constructed architectures with arenes or pyridinium salts as backbones can be further enhanced by forming fused conjugated systems to substantially change the electronic and optical properties.…”

“…It is worth noting that due to the ionic feature of pyrylium salts, these compounds are insoluble in many organic solvents like toluene or ethyl ether, and can be easily purified by washing with such solvents. With the positively charged oxygen atom, pyrylium salts are strongly reactive towards diverse nucleophiles to readily form various heterocyclic groups, including furan 7 , pyridines 34 , phosphinines [35][36][37] , pyridinium salts 38,39 , thiopyrylium salts 40 and betaine dyes 41,42 (Figure 3). As a result, pyrylium salts chemistry provides a versatile platform for constructing different types of…”