111772-62-4Relevant articles and documents
Structural and spectroscopic characterization of Cu(salen) complexes bearing long alkoxy chains
Raeisaenen, Minna T.,Klinga, Martti,Leskelae, Markku,Nieger, Martin,Repo, Timo
, p. 4280 - 4289 (2010)
Cu(II) salen (salen = N,N'-ethylene-bis(salicylideneimine)) complexes bearing alkoxy chains of C12 (1) and C10 (2) in the salicylidene moieties were synthesized and subsequently characterized by several independent methods: single cr
Zinc(II)-salphen complexes bearing long alkoxy side arms: Synthesis, solvent dependent aggregation, and spacer group substituent effect on mesomorphism and photophysical property
Chakraborty, Sutapa,Mondal, Paritosh,Krishna Prasad,Shankar Rao,Bhattacharjee, Chira R.
, p. 290 - 301 (2017)
Hemi-disc shaped zinc(II) complexes of two new series of halogen-substituted ‘salphen’ type Schiff base ligands [ZnL]; H2L = [N,N′-Bis(4-n-alkoxysalicylidene)-4-fluoro/bromo-1,2-diaminobenzene] (n = 12, 14, 16) have been synthesized and their mesomorphism and photophysical properties investigated. The ligands and zinc(II) complexes displayed columnar mesophases over a much wider temperature range. Depending on the halogen substitution at the ligand's spacer; different variant of columnar phases were exhibited by the ligands and the zinc(II) complexes. The ligands and the complexes displayed fluorescence at ambient temperature in the blue-green region with moderate to low intensity. Density functional theory (DFT) calculations indicated a distorted square-planar geometry around the zinc(II) center in the complexes. The coordinative unsaturation of the zinc(II) center in these complexes leads to interesting aggregation properties in a dilute solution of non-coordinating solvents. However, in coordinating solvent, axial coordination to the zinc(II) ion occurred leading to complete de-aggregation to monomer.
Induction of Mesomorphism through Supramolecular Assembly in Metal Coordination Compounds of “salphen”-Type Schiff Bases: Photoluminescence and Solvatochromism
Chakraborty, Sutapa,Mondal, Paritosh,Prasad, S. Krishna,Rao, D. S. Shankar,Bhattacharjee, Chira R.
, p. 4604 - 4614 (2016)
Mesomorphism induced by metal (VO2+, Ni2+, Cu2+and Zn2+) coordination and its influence on the photophysical properties of a new series of symmetric “salphen”-type N,N-bis(4-n-alkoxysalicylidene)-4,5-dichloro-1,2-phenylenediamine ligands (n = 12, 14, 16) bearing highly electronegative spacer substituents and alkoxy arms of varied length have been investigated. The mesomorphism has been probed by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), and variable-temperature powder X-ray diffraction (XRD). The Schiff base ligands are non-mesomorphic; however, coordination to NiIIand ZnIIions induces columnar mesomorphism, this being stable down to room temperature in the latter case. Interestingly, the complexes of CuIIand VOIVdid not show any mesomorphism. The free ligands and the ZnIIcomplexes are luminescent both in the condensed state and in solution, with emission maxima in the condensed state being significantly red-shifted with respect to those in solution. The energy-optimized structure of a representative ZnIIcomplex was ascertained to be distorted square planar in a DFT study employing the GAUSSIAN 09 program. The ZnIIand VOIVcomplexes exhibited solvatochromic effects, showing interesting aggregation behavior in the former case.
Coumarins as powerful photosensitizers for the cationic polymerization of epoxy-silicones under near-UV and visible light and applications for 3D printing technology
Abdallah, Mira,Dumur, Frédéric,Hijazi, Akram,Lalevée, Jacques
, (2020)
In this study, eight coumarins (coumarins 1–8) are proposed as near-UV and blue light sensitive photoinitiators/photosensitizers for the cationic polymerization (CP) of epoxysilicones when combined with 4-isopropyl-4’-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate (IOD). Among these coumarins, four of them (coumarins 1, 2, 6 and 8) have never been reported in the literature, i.e., these structures have been specifically designed to act as photoinitiators for silicones upon near UV and visible irradiation. Good final reactive epoxy function conversions (FCs) and also high rates of polymerization (Rp) were achieved in the presence of the newly proposed coumarin-based systems. The polymers generated from the photopolymerization of epoxysilicones can be considered as attractive candidates for several applications such as: elastomers, coatings, adhesives, and so on. The goal of this study focuses also on the comparison of the new proposed coumarins with well-established photosensitizers i.e., 1-chloro-4-propoxythioxanthone (CPTX), 9,10-dibutoxyanthracene (DBA) or some commercial coumarins (Com. Coum). As example of their high performance, the new proposed coumarins were also used for laser write experiments upon irradiation with a laser diode at 405 nm in order to develop new cationic 3D printing systems.
Thermal, optical and Photophysical behaviour of some Mesogenic Benzimidazole-based Schiff-bases
Yerrasani, Rajasekhar,Karunakar,Dubey, Ragini,Singh, Angad Kumar,Rao
, p. 214 - 218 (2017)
A series of luminescent benzimidazole-based Schiff-bases, 5-(alkyloxy)-2-(((2-(4-(alkyloxy)phenyl)-1H–benzimidazol-5-yl)imino)methyl)phenol, with different alkyl chains was synthesized and characterized by 1H & 13C NMR, UV–Vis, fluorescence and mass spectrometry. All the compounds were found to be mesogenic (smectic A1), as studied by POM and DSC techniques, and their green emission was implied by fluorescence studies. Electrochemical study of one of the compounds, 3d, shows a band gap of 2.56 eV with HOMO and LUMO energy levels at ? 5.22 eV and ? 2.67 eV, respectively.
Fine-tuning of relative metal - Metal distances within highly ordered chiral 2D nanopatterns
Zell, Philipp,Moegele, Florian,Ziener, Ulrich,Rieger, Bernhard
, p. 3847 - 3857 (2006)
The two-dimensional nano-patterning of a series of neutral alkoxy/alkyl-functionalised bis(salicylaldehydato)/bis(aldiminato)copper(II) and -palladium(II) complexes at a liquid/solid (highly oriented pyrolytic graphite, HOPG) interface has been studied by scanning tunnelling microscopy (STM). The relative metal - metal distances were tuned stepwise in two dimensions by ligand design. Exchange of the carbonyl O-atom for NH or N-alkyl units effects different intermolecular interactions such as weak hydrogen bonds and steric effects that deter mine, together with the van der Waals forces between the alkyl chains, the relative arrangements of the complexes. Further variation of the length and position of the alkoxy side chains as well as the exchange of CuII for PdII affords an absolute fine-tuning of the surface structures. Highly resolved STM images of the resultant highly ordered adlayers allow us to establish detailed models of the molecular 2D arrays and to classify them into three basic chiral pattern types. Homochirality within the individual domains is induced by the highly regular deposition of the prochiral complexes from the same enantiotopic face. In the case of the C12 O-substituted bis(salicylaldiminato) (NH) CuII complex Cu5, a secondary structure occurs as a racemic mixture of two chiral surface species deposited in a distinct alternating order.
Schiff base of 4-n-alkoxy-2-hydroxy benzaldehyde with 4-amino acetophenone and their Cu(II) complexes: synthesis, characterization and mesomorphic behavior
Nakum, Kiran J.,Katariya, Kanubhai D.,Jadeja,Prajapati
, p. 1 - 13 (2019)
New homologous series of Schiff’s base of 4-n-Alkoxy-2-hydroxy benzaldehyde (n = 2 to 8, 10, 12, 14, 16, 18) with 4-amino acetophenone and their Cu(II) metal complexes have been synthesized. The compounds were characterized using various spectroscopic techniques including FT-IR, 1H-NMR, 13C-NMR. Mesomorphic properties of these compounds have been investigated with polarizing optical microscope and differential scanning calorimeter. These compounds exhibit wide range SmA phase as confirmed by their typical optical texture under polarizing microscope.
Polarization effect in luminescent mesogenic BF2 complexes derived from heterocyclic benzothiazoles
Hsu, Yuan?Chun,Wang, Chun?Yang,Hsiao, Pei?Chi,Cai, Yi-Hong,Lee, Gene?Hsiang,Lai, Chung K.
, (2019/12/09)
Two series of benzo(thia)xazoles 1–2 and one series of boron difluoride complexes 2-BF2 derived from benzothiazoles 2 were reported, and their mesomorphic and optical properties were investigated. The crystal and molecular structures of compound 2 and 2-BF2 (all n = 8) were determined by means of X?ray structural analysis, and both crystallize in the triclinic P-1 and monoclinic P21/c. The geometry at boron center is perfectly tetrahedral, and the overall molecular shapes are considered as rod?shape. Both benzo(thia)xazoles 1 and 2 exhibited N or/and SmC phase, and boron complexes 2-BF2 formed N or/and SmC phase. Benzothiazoles 2 showed a much wider temperature range of mesophase than those of benzoxazoles 1, which were attributed to the better polarization by sulfur atom incorporated. Boron complexes 2-BF2 (n = 10, 12) emitted a yellow?to?green emission at λmax = 569–571 nm in CH2Cl2. This is the first mesogenic BF2 complexes derived from benzothiazoles.
