Synthesis and optical properties of N→Ga coordinated gallium boroxines

• Published in: Dalton transactions : an international journal of inorganic chemistry Vol. 5; no. 48; pp. 18164 - 18172
• Main Authors: Milasheuskaya, Yaraslava, Schwarz, Ji í, Dostál, Libor, R i ková, Zdenka, Bouška, Marek, Olmrová Zmrhalová, Zuzana, Syrový, Tomáš, Jambor, Roman
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 14.12.2021
• Subjects: Electrical resistivity; Gallium; Molecular structure; Optical properties; Refractivity; Spin coating; Thin films
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d1dt02975d

Reactions of the N,C,N-chelated organogallium amide LGa(NEt 2 ) 2 ( 1 ), where L is {2,6-(Me 2 NCH 2 ) 2 C 6 H 3 } − , with organoboronic acids RB(OH) 2 yielded molecular gallium boroxines LGa(O 3 B 2 R 2 ) ( 2 : R = OH, 3 : R = Ph, 4 : R = 4-MeO-C 6 H 4 , 5 : R = 4-CHO-C 6 H 4 , 6 : R = Fc), neutral analogues of gallaborates. The molecular structures revealed the presence of a six-membered central GaB 2 O 3 ring. The film forming properties of 5 allowed the deposition of transparent thin films by a spin coating method. The thicknesses, refractive index, energy of the optical gap ( E opt g ), activation energy of surface electrical conductivity ( E s a ) and pre-exponential factor ( σ 0 ) of the thin layers of 5 were measured and they are close to those found for related oxygen glass. Finally, GBO 5 was also used as an additive to printing ink and a thin film of 5 was prepared by the gravure printing technique. Molecular gallium boroxine was used for the deposition of transparent thin layers by spin coating and gravure printing. The optical properties of thin layers are similar to those of related Ga doped borate glasses.