Photoluminescence: Design and Integration in Electro‐Optic Devices of Highly Efficient and Robust Red‐NIR Phosphorescent Nematic Hybrid Liquid Crystals Containing [Mo₆I₈(OCOC_nF_2n+1)₆]²⁻ (n = 1, 2, 3) Nanoclusters (Adv. Funct. Mater. 31/2015)

Abstract

As shown by L. Dupont, Y. Molard, and co‐workers on page 4966, the functionalization of [Mo6I8(CnF2n+1COO)6]2− (n = 1, 2, 3) red–near‐infrared phosphorescent nanocluster units with specific organic cations leads to a nematic liquid crystalline material that can be homogeneously mixed with E7 commercial liquid crystal. Integration in electro‐controlled devices modulates the cluster photoluminescence intensity, demonstrating the potential of these hybrid materials for photonic or optoelectronic applications.

Polarized Phosphorescence of Isotropic and Metal‐Based Clustomesogens Dispersed into Chiral Nematic Liquid Crystalline Films

“…The high twisting power chiral dopant BDH1281 (Merck) was dispersed into the LCs to form a chiral nematic phase with a right‐handed helical structure. The clustomesogens used were Trisel 2 [Mo 6 I 8 (OCOC 2 F 5 ) 6 ] and Trisel 2 [Mo 6 I 8 (OCOC 3 F 7 ) 6 ], synthesized by a metathesis reaction as described by Prévôt et al and repeated in the Supporting Information.…”

“…In contrast, recently developed transition metal clustomesogens composed of mesomorphic organic compounds and octahedral molybdenum clusters appear to circumvent some of these problems . They have been shown to be stable to continuous wave illumination, may be dispersed at high concentrations by weight into LC materials and are thermally stable to temperatures well above the LC clearing point . They exhibit high quantum yields (0.59 and 1 were reported in solution for ( n Bu 4 N) 2 Mo 6 I 8 (OCOC 3 F 7 ) 6 and ( n Bu 4 N) 2 Mo 6 I 8 (OCOCF 3 ) 6 , respectively and strong photoluminescence (PL) in nematic LC materials .…”

“…The two clustomesogens used here were Trisel 2 [Mo 6 I 8 (OCOC 2 F 5 ) 6 ] and Trisel 2 [Mo 6 I 8 (OCOC 3 F 7 ) 6 ] (Figure S1, Supporting Information), both contain the [Mo 6 I 8 (OCOC n F 2 n +1 )] 2− ( n = 2, 3) anionic cluster unit—chosen for the excellent photophysical properties reported for similar compounds . The two clustomesogens differ in the length of their fluorinated apical ligands but exhibit very similar properties such as the same quantum yield (0.7) . The two materials were found to have indistinguishable emission and absorption windows.…”