17026-49-2Relevant academic research and scientific papers
A New Synthesis of Oxacalixarene Macrocycles and Alkali-Metal-Binding Studies
Hampton, Philip D.,Bencze, Zsolt,Tong, Weidong,Daitch, Charles E.
, p. 4838 - 4843 (1994)
The title oxacalixarene macrocycles 1 have been synthesized in yields of 12-32percent by an acid-catalyzed, high-dilution condensation of 2,6-bis(hydroxymethyl)-p-subtituted-phenols, where R = t-Bu, i-Pr, Et, Me, and Cl.The macrocycles are isolated in high purity without chromatography, as the sodium or potassium salts of their monoanions.Metal-binding studies indicate that, like the related calixarenes, the oxacalixarenes bind alkali metals only in the presence of base (Na(1+) ca.K(1+) > Li(1+)).
Synthesis, structure, luminescent property and theoretical studies of 4-chloro-2,6-bis[(3,5-dimethyl-1H-pyrazol-1-yl)methyl]phenol
Tang, Li-Zhipeng,Tao, Feng,Cheng, Mei-Ling,Liu, Qi
, p. 528 - 531 (2014)
4-Chloro-2,6-bis[(3,5-dimethyl-1H-pyrazol-1-yl)methyl]phenol has been synthesised and characterised, including by single-crystal X-ray diffraction. The benzene ring system is planar and makes dihedral angles of 88.90°(0.14) and 59.84°(0.11) with two pyrazole rings, respectively, and the two pyrazole rings are arranged trans to each other with the dihedral angles 87.22°(0.15). The luminescent property of the title compound was investigated. The molecular structure of the title compound has been optimised by density functional theory with B3LYP/6-31G (d, p) level, the optimised geometer parameters and vibrational frequencies are consistent with the experiment data.
Magnetic and structural properties of dinuclear singly bridged-phenoxido metal(II) complexes
Massoud, Salah S.,Spell, Mark,Ledet, Catherine C.,Junk, Thomas,Herchel, Radovan,Fischer, Roland C.,Trvnek, Zdenk,Mautner, Franz A.
, p. 2110 - 2121 (2015/01/30)
The reaction of a methanolic solution containing the bi-compartmental phenolic ligand 2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-chlorophenol (LCl-OH) with MCl2·nH2O in the presence of NH4PF6 or NaClO4 afforded the dinuclear bridged-phenoxido dichlorido-metal(ii) complexes [Co2(μ-LClO)(H2O)2Cl2][Co2(μ-LClO)(MeOH)2Cl2](PF6)2 (1), [Ni2(μ-LClO)(MeOH)2Cl2]PF6 (2), [Ni2(μ-LClO)(MeOH)(H2O)Cl2]ClO4·1.25H2O (3), [Cu2(μ-LClO)Cl2]PF6·1/2MeOH (4) and [Zn2(μ-LClO)Cl2]PF6·MeOH (5). The complexes were characterized by elemental microanalyses, conductivity measurements, IR and UV-Vis spectroscopy, mass spectrometry and single crystal X-ray crystallography. Each M(ii) center within the dinuclear complex cations is octahedrally coordinated in complexes 1-3, and five-coordinated distorted square pyramidal in 4 and 5. Magnetic susceptibility measurements at variable temperature of the complexes 1-4 revealed weak to moderate antiferromagnetic coupling with |J| values = 8.38, 39.0, 30.2 and 0.79 cm-1, respectively. The results of DFT calculations correlate well with the experimentally determined antiferromagnetic coupling and show that the magnetic exchange coupling occurs mainly through the phenoxido bridge M-O-M. Implications of geometry around the central metal ion, M...M distance, M-O-M bond angle and overlapping of magnetic orbitals on the magnetic exchange coupling are discussed.
Coordination cluster analogues of the high-Spin [Mn19] system with functionalized 2,6-Bis(hydroxymethyl)phenol ligands
Mameri, Samir,Ako, Ayuk M.,Yesil, Fatma,Hibert, Marcel,Lan, Yanhua,Anson, Christopher E.,Powell, Annie K.
, p. 4326 - 4334 (2015/03/30)
A series of 2,6-bis(hydroxymethyl)-4-R-phenol ligands (H3LR; R = H, F, Cl, Br, I, Ph, NH2, NO2, SMe) have either been newly synthesized or the existing syntheses have been significantly improved to investigate ligand-functionalized analogues of the previously published coordination cluster [MnIII12MnII7(μ4-O)8(μ3-N3)8(HLMe)12(MeCN)6]Cl2·10MeOH·MeCN (1) with S = 83/2. The crystal structures and magnetic properties of three such Mn19 clusters, namely, [MnIII12MnII7(μ4-O)8(HLH)12(μ3-Cl)7(μ3-OMe)(MeOH)6]Cl2·16H2O·10MeOH·MeCN (3), [MnIII12MnII7(μ4-O)8(HLI)12(μ3-N3)8(MeOH)6](O2CH)2·16MeOH·10MeCN (4) and [MnIII12MnII7(μ4-O)8(μ3-Cl)7.7(μ3-OMe)0.3(HLSMe)12(MeOH)6]Cl2·27MeOH (5) are reported and compared to those of the parent cluster. When these ligands are functionalized with substituents of moderate electronegativity, it is possible to synthesize Mn19 analogues; however, when such ligands bear highly electron-donating (amino) or -withdrawing (nitro) substituents, the Mn19 analogues are no longer accessible. The Mn19 cluster framework is both magnetically and structurally robust with respect to the electron-donor/acceptor characteristics of the ligand substituent; therefore, the Mn19 system is an excellent platform for peripheral chemical engineering. The robustness of the inorganic {MnIII12MnII7(μ4-O)8} core of Mn19 systems with variously functionalized encapsulating ligands is demonstrated by the invariance of the record S = 83/2 spin state. Chemical modification aimed towards attaching the molecule to various substrates does not interfere with the electronic structure.
Efficient synthesis of (R)-ochratoxin alpha, the key precursor to the mycotoxin ochratoxin A
Lenz, Cesar Antonio,Rychlik, Michael
supporting information, p. 883 - 886 (2013/02/25)
Two new routes for the synthesis of enantiomerically pure ochratoxin alpha ((3R)-OTα) are presented, which is the key intermediate for the synthesis of ochratoxin A (OTA) by coupling reaction with the amino acid l-phenylalanine. The key step of both routes is the one pot directed ortho-metalation/alkylation/ lactonization of unprotected and suitably functionalized aromatic carboxylic acids, using lithium tetramethylpiperidide (LTMP) and (R)-propylene oxide.
VISIBLE LIGHT ABSORBERS FOR OPHTHALMIC LENS MATERIALS
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Paragraph 0032, (2013/09/12)
Azo compounds that block visible light are disclosed. These light absorbers are particularly suitable for use in intraocular lens materials.
VISIBLE LIGHT ABSORBERS FOR OPHTHALMIC LENS MATERIALS
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, (2011/01/12)
Azo compounds that block visible light are disclosed. These light absorbers are particularly suitable for use in intraocular lens materials.
Mononuclear copper(ii) complexes with 3,5-substituted-4-salicylidene-amino- 3,5-dimethyl-1,2,4-triazole: Synthesis, structure and potent inhibition of protein tyrosine phosphatases
Ma, Ling,Lu, Liping,Zhu, Miaoli,Wang, Qingming,Li, Ying,Xing, Shu,Fu, Xueqi,Gao, Zengqiang,Dong, Yuhui
experimental part, p. 6532 - 6540 (2011/08/03)
Six copper complexes of Schiff base ligands containing 3,5-substituted-4- salicylideneamino-3,5-dimethyl-1,2,4-triazole have been synthesized and well characterized. The structures of complexes 1 and 2 were determined by X-ray crystal analysis. Fluorescence and potentiometric study indicated that in the physiological pH range, one ligand was dissociated from the complexes to form 1:1 mononucleus copper complexes. The complexes potently inhibit protein tyrosine phosphatase 1B (PTP1B), T-cell protein tyrosine phosphatase (TCPTP), megakaryocyte protein tyrosine phosphatase 2 (PTP-MEG2) and Src homology phosphatase 1 (SHP-1) with 3-4 fold selectivity against PTP1B over TCPTP and PTP-MEG2, and 3-9 fold over SHP-1, but display almost no inhibition against Src homology phosphatase 2 (SHP-2). Complex 1 inhibits PTP1B with a competitive model with Ki of 30 nM. Substitution with small groups at the phenyl of the ligand does not obviously influence the inhibitory ability of the complexes.
Self-assembly from metal-organic vesicles to globular networks: Metallogel-mediated phenylation of indole with phenyl boronic acid
Yang, Li,Luo, Liang,Zhang, Shuai,Su, Xiaoyu,Lan, Jingbo,Chen, Chi-Tien,You, Jingsong
supporting information; scheme or table, p. 3938 - 3940 (2010/07/14)
Self-assembly of the conformationally flexible bismethylimidazolyl ligands with Pd(OAc)2 is described. Depending on whether the ligands provide the hydrogen bonding donor, a switching of metal-organic vesicles to globular networks gelating solvents is achieved. The metallogels exhibit catalytic activity for the cross-coupling of indole with phenyl boronic acid.
Preparation of new phenol-based acyclic ligands with double set of coordination sites
Ghaffarinia,Golchoubian
, p. 83 - 87 (2007/10/03)
A convenient four-step preparation of the two compartmental ligands 1,6-bis(2-pyridyl)-2,5-bis(2-hydroxy-3-hydroxymethyl-5-chlorobenzyl)-2, 5-diazahexane 3a and 1,7-bis (2-pyridyl)-2,6-bis(2-hydroxy-3-hydroxymethyl-5- chlorobenzyl)-2,6-diazaheptane 3b starting from 4-chlorophenol 4 is reported. Compound 4 was converted to triol 5 which was then protected to 2,2-dimethyl-6-chloro-8-(hydroxymethyl)benzo-1,3-dioxin 6 with 2-methoxy propene. Compound 6 was chlorinated to 2,2-dimethyl-6-chloro-8-(chloromethyl) benzo-1,3-dioxin 7 and then reacted with 1,6-bis(2-pyridyl)-2,5-diazahexane or 1,7-bis(2-pyridyl)-2,6-diazaheptane in the presence of Na2CO 3 in dioxane. Subsequent acid hydrolysis gave 3a and 3b, respectively. The total yields were 38%.
