Lanthanoid poly(pyrazol-1-yl) borate complexes

Lanthanide Cerium(III) Tris(pyrazolyl)borate Complexes: Efficient Blue Emitters for Doublet Organic Light-Emitting Diodes

“…The B–N bond cleavage during coordination results from big steric hindrance of the Tp 3Me,5Me ligand, which twists the pyrazolyl rings and weakens B–N bonds . The case of no substituents on the Tp ligand leads to complex 1 , which is a classic nine-coordinated complex comprised of three Tp ligands as a result of much less tension in the ligands. , Complexes 2-Me and 2-Br are also nine coordinated because the substituents on the 4 site of the pyrazolyl ring have basically no impact on the coordination sphere. Substituents on the boron ought to have a small effect, such as in complexes 4-Pz and 4- n Bu ; however, we still found complex 4- i Pr as an exception.…”

“…Complexes 1 and 3-Me have been reported before; nevertheless, their luminescent properties were investigated here for the first time. 26,28,29 All of the Ce(III) complexes showed bright blue luminescence with high PLQYs over 95% under ultraviolet excitation. The photophysical properties of these complexes in the solid powder are shown in Figure 2.…”

Intraligand fluorescence and phosphorescence of tris(pyrazolyl) hydridoborate complexes

“…Previously, it has been assumed that such Tp À IL states do not play any important role [14] since the longest-wavelength pp * absorptions appear at rather high energies (k max = 215 nm) [9,13] but any luminescence from such IL states has apparently never been examined. We explored this possibility and selected the compounds KTp (Aldrich), GdTp 3 [17,18] and PPh 3 AgTp [19] for the present study. The choice of GdTp 3 and PPh 3 AgTp is based on various considerations.…”

Eight-co-ordination in lanthanide pyrazolylborate chemistry: crystal structures of [LaTpMe,Me2(MeCN)(O3SCF3)] ·MeCN, [NdTpMe,Me2(MeCN)2][O3SCF 3] and [LaTpMe,Me2(NO3)]·MeCN [TpMe,Me = tris(3,5-dimethylpyrazolyl) hydroborate]

“…Complexes of the type [LnTp 2 X] (X = unidentate ligand) were found to be unstable in solution and to undergo comparatively rapid redistribution reactions. 3 By contrast, when anionic bidentate ligands (X᎐X) were used in place of X, complexes of the type [LnTp 2 (X᎐X)] were obtained. Intermolecular exchange was suppressed to the point that it was only observable on an NMR time-scale and well behaved eight-co-ordinate complexes were isolated.…”