Related Experiment Video
Updated: Jun 28, 2026

Scale-up Chemical Synthesis of Thermally-activated Delayed Fluorescence Emitters Based on the Dibenzothiophene-S,S-Dioxide Core
Published on: October 24, 2017
Benz(2-heteroaryl)cyanoximes and their Tl(i) complexes: new room temperature blue emitters
Olesya T Ilkun1, Stephen J Archibald, Charles L Barnes
1Department of Chemistry, Missouri State University, Temple Hall 456, Springfield, MO 65897, USA.
Abstract:
A series of five 2-heteroarylcyanoximes such as: alpha-oximino-(2-benzimidazolyl)acetonitrile (HBIHCO), alpha-oximino-(N-methy-l-2-benzimidazolyl)acetonitrile (HBIMCO), alpha-oximino-(2-benzoxazolyl)acetonitrile (HBOCO), alpha-oximino-(2-benzothiazolyl)acetonitrile (HBTCO) and alpha-oximino-(2-quinolyl)acetonitrile (HQCO) and their monovalent thallium(i) complexes were synthesized and characterized using spectroscopic methods ((1)H, (13)C NMR, IR, UV-visible, mass-spectrometry) and X-ray analysis. The HBIMCO (as monohydrate) adopts planar trans-anti configuration in the solid state. The crystal structure of "HBOCO" revealed the presence of nitroso anion a, BOCO(-), and protonated oxime cation b, H(2)BOCO(+), that form a H-bonded dimer in the unit cell. Both molecules adopt planar structures, but different configurations: cis-anti in the molecule a, and trans-anti for b. This is the first reported case of a zwitterionic pair in oximes and the coexistence of the two geometrical cis/trans isomers in the same crystal. All 2-heteroarylcyanoximes form yellow anions upon deprotonation, which exhibit significant negative solvatochromism in solution. Heterogeneous reactions between hot aqueous solutions of Tl(2)CO(3) and solid protonated 2-heteroarylcyanoximes HL afford yellow TlL. The crystal structure of Tl(BTCO) shows the formation of centrosymmetrical dimers, which connect with each other to form a double-stranded one-dimensional coordination polymer. The oxygen atom of the oxime group acts as a bridge between the three different Tl(i) centers. The anion is non-planar and adopts a trans-anti configuration in the complex. The polymeric motif in the complex represents a ladder-type structure. Staggered pi-pi interactions between benzothiazolyl groups provide additional stabilization of the structure. Both organic ligands and their Tl(i) complexes exhibit strong room temperature blue emission in the solid state.
More Related Videos
14:11Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
Published on: June 10, 2021
12:27Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes
Published on: September 8, 2013
Related Concept Videos
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
Cycloaddition Reactions: MO Requirements for Photochemical Activation
Diazonium Group Substitution: –OH and –H
Electrophilic Aromatic Substitution: Nitration of Benzene