Synthesis of π-extended B ← N coordinated phenanthroimidazole dimers and their linear and nonlinear optical properties

Abstract

B ← N coordinated phenanthroimidazole dimers exhibit excellent fluorescence quantum yields in solution and conjugation length dependant two-photon-absorption properties.

Synthesis, Photophysical, Electrochemical, and Non‐linear Optical Properties of Triaryl Pyrazole‐based B‐N Coordinated Boron Compounds

“…In all these compounds, the boron atom adopts a slightly distorted tetrahedral geometry and deviate from the five‐membered plane defined by C 2 N 2 B (boron atom, pyrazole two nitrogen atoms, and phenyl carbons directly attached to boron and nitrogen); the distance ranging from 0.0072 to 0.0667 Å (Table S2). The B−N and B−C distances are in the typical range (Table S1) and are consistent with values reported in the literature [7f–i] . The interplanar angle between the N‐phenyl (Plane A) and pyrazole is 13.09 ° (for 12 ), 11.037 ° (for 13 ), 5.851 ° & 1.492 ° (for 14 ), 7.52 ° (for 15 ), 9.959 ° (for 16 ), and 3.182 ° (for 17) which indicates pyrazole and N‐phenyl skeleton have slight distortion.…”

“…Pyrazole based B−N coordinated dibromoborane compounds 11 a – 17 a were prepared from their corresponding pyrazole ligands through an electrophilic aromatic borylation reaction with BBr 3 under basic condition (i ‐Pr 2 NEt) [7f–i] . Without further purification, the pyrazole‐dibromoborane compounds ( 11 a – 17 a ) were treated with trimethylaluminum (AlMe 3 ) to afford the desired products 11 – 17 in moderate yields (Scheme 2).…”

“…Use of tri‐coordinated boranes and amines as acceptor‐donor have been exploited in nonlinear optical materials by Marder, [19] Perry, [20] Fang, [21] Lambert, [22] Jäkle, [23] however, utilization of B−N coordinated tetra‐coordinated boranes are scarcely studied as NLO of materials. Recently, we reported synthesis of phenanthroimidazole and triarylpyrazole based B−N coordinated dimers and their linear and non‐linear properties [7f,g] . In this work, we describe synthesis of monomeric triarylpyrazolyl B−N coordinated boron compounds their photophysical, electrochemical, and non‐linear optical properties.…”

Tetra-Coordinated Boron-Functionalized Phenanthroimidazole-Based Zinc Salen as a Photocatalyst for the Cycloaddition of CO2 and Epoxides

“…We recently reported tetra-coordinated boron-functionalized phenanthroimidazoles and studied their linear and nonlinear optical properties . We have now coupled this tetra-coordinated boron motif with a zinc­(II) salen and utilized the hybrid system for the chemical transformation of CO 2 and oxiranes to produce cyclic carbonates using visible light.…”

Recent advances in the synthesis of luminescent tetra-coordinated boron compounds

“…13; 106-109). 119,120 Photophysical studies revealed that the phenanthroimidazole and triaryl pyrazole based dimers exhibited considerable red shift absorption over the monomeric borylated systems due to the increased conjugation length. Fluorescence experiments of phenanthroimidazole dimers showed intense emission maxima ranging from 418 nm to 480 nm with excellent quantum yields up to 99% in the solution state and moderate quantum yields in the solid state.…”