X-ray crystallographic study of three (N→B)-borinates prepared from 8-hydroxyquinoline and 2-hydroxypyridine

Four-coordinate boron compounds derived from 2-(2-pyridyl)phenol ligand as novel hole-blocking materials for phosphorescent OLEDs

“…The O-B-N, O-B-C13, and O-B-C19 angles and the sum of these angles of 324.7°around the boron center in 2 is rather deviated from the ideal values of 109.5°and 328.5°, respectively, for the tetrahedral geometry, indicating the pseudo-tetrahedral geometry around the boron center. The latter angle is also larger than those observed in Ph 2 Bq (314.8°for molecule I and 317.7°for molecule II) [18] and (C 6 F 5 ) 2 Bq (319.6°) [17]. This finding could be mainly attributed to the increased O-B-N bite angle in 2 (104.97(15)°) by ca.…”

“…8.4°and 5.5°, respectively, when compared to those in Ph 2 Bq (96.6(7)°for molecule I and 96.7(8)°for molecule II) [18] and (C 6 F 5 ) 2 Bq (99.43(13)°) [17], probably owing to the six-membered ring nature of 1. While the B-O bond length of 1.480(2) Å in 2 is shorter than that in Ph 2 Bq (1.56(1) Å), the B-C and B-N bonds are slightly lengthened in comparison with those in Ph 2 Bq within 0.02 Å [18]. It is interesting to note that the phenolate and pyridine rings of 2-(2-pyridyl)phenolate moiety in 2 are distorted to form a dihedral angle (h) of 20°.…”

Imino Diels–Alder reaction of boronates: A new route to 3,4-dihydroquinolines

“…B bond lengths for compounds 4c and 4d are 1.578(5) and 1.590(3) Å , respectively, which are significantly shorter than those reported for boronates derived from 8-hydroxyquinoline and diphenylboronic 1.61(1), 9-BBN 1.637(3) [20] or diethylboronic acid 1.636(5) Å [21].…”

“…The torsion angle for the NCCO fragment in the fivemembered boroxazolidine ring of 4c (À3.4°) and 4d (À2.6°) showed a value closer to that of boronate 2b À2.3(6) than to those reported for derivatives prepared from 8-hydroxyquinoline and diphenylboronic acid (À0.7) [20]. The five-membered ring in 4c and 4d is …”

The effect of fluorination on the luminescent behaviour of 8-hydroxyquinoline boron compounds

“…26,36 We have recently reported the synthesis and characterisation of (C 6 F 5 ) 2 BQ 3. Table 2 and representative spectra are shown in Figure 2.…”