Experimental and computational evidence of the intermolecular motifs in the crystal packing of luminescent pentacoordinated gallium(III) complexes.
This paper reports the synthesis, characterization, photophysical and structural properties of the homologous series of good emitting pentacoordinated GaQ'2L complexes 1-3, where Q' is 2-methyl-quinolin-8-olate and L is a phenolate substituted in para position with respect to the oxygen donor atom. A combined approach between the experimental structural analysis (i.e. the molecular fragments involved in intermolecular pi-pi interactions) and the computational study (i.e. the nature of the molecular orbitals residing therein) is discussed in order to compare the charge transport aptitude of complexes 1-3, in relation to the facing of their LUMO/LUMO, HOMO/HOMO and HOMO/LUMO arising from the molecular packing. The different phenolate ligands significantly change the packing characteristics of 1-3, with indirect effects on the electron hopping kinetics responsible for conduction in amorphous thin films. The observed preference for pyridyl-pyridyl stacking proves a faster electron conduction in comparison to hole conduction in the three complexes studied.
Crispini
Alessandra
A
Centro di Eccellenza CEMIF.CAL-LASCAMM, CR-INSTM Unità della Calabria, Dipartimento di Chimica, Università della Calabria, I-87036, Arcavacata di Rende (CS), Italy.
Aiello
Iolinda
I
La Deda
Massimo
M
De Franco
Irene
I
Amati
Mario
M
Lelj
Francesco
F
Ghedini
Mauro
M
D003198:Computer Simulation; D003460:Crystallization; D018360:Crystallography, X-Ray; D005708:Gallium / Q000737:chemistry*; D049449:Luminescence; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011789:Quantum Theory; D013237:Stereoisomerism
D009942:Organometallic Compounds; D005708:Gallium