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81.
He Zhu Dr. Qiang Chen Dr. Igor Rončević Dr. Kirsten E. Christensen Prof. Harry L. Anderson 《Angewandte Chemie (International ed. in English)》2023,62(31):e202307035
π-Conjugated nanoribbons attract interest because of their unusual electronic structures and charge-transport behavior. Here, we report the synthesis of a series of fully edge-fused porphyrin-anthracene oligomeric ribbons (dimer and trimer), together with a computational study of the corresponding infinite polymer. The porphyrin dimer and trimer were synthesized in high yield, via oxidative cyclodehydrogenation of singly linked precursors, using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and trifluoromethanesulfonic acid (TfOH). The crystal structure of the dimer shows that the central π-system is flat, with a slight S-shaped wave distortion at each porphyrin terminal. The extended π-conjugation causes a dramatic red-shift in the absorption spectra: the absorption maxima of the fused dimer and trimer appear at 1188 nm and 1642 nm, respectively (for the nickel complexes dissolved in toluene). The coordinated metal in the dimer was changed from Ni to Mg, using p-tolylmagnesium bromide, providing access to free-base and Zn complexes. These results open a versatile avenue to longer π-conjugated nanoribbons with integrated metalloporphyrin units. 相似文献
82.
Electronic and vibrational spectra of mimetite, arsenian pyromorphite and hedyphane minerals have been analysed and the spectra related to the mimetite and arsenian pyromorphite and hedyphane mineral structure. The chief spectral feature in the electronic spectra at ∼10 000 cm−1 (1.00 μm) with variable band position and intensity results from the ferrous ion. The splitting of Fe(II) band is large in mimetites with a separation of 1415 cm−1. An additional band shown by arsenian pyromorphite at 10 735 cm−1 (0.93 μm) is assigned to Cu(II) dd-transition. The substitution of Fe(II) causes a blue shift for Cu(II) band in mimetites and the intensity of this band is enhanced at ∼11 140 cm−1 (0.90 μm). The change in colour from brown to orange-yellow relates to the amount of Cu and/or Fe impurities in the mimetite minerals. 相似文献
83.
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85.
Jiliang Wang Hongfeng Li Peng Chen Meiqi Zhang Wenbin Sun Pengfei Yan 《无机化学与普通化学杂志》2016,642(5):368-371
The reaction of 2‐aldehyde‐8‐hydroxyquinoline, histamine, and YbX3 · 6H2O (X = NO3–, ClO4–) affords two ytterbium complexes [Yb(nma)2] · ClO4 · 2CH2Cl2 ( 1 ) and [Yb(nma)(NO3)2(DMSO)] · CH3OH ( 2 ) (Hnma = N‐(2‐(8‐hydroxylquinolinyl)methane(2‐(4‐imidazolyl)ethanamine))). The crystal structures were determined by X‐ray diffraction and it has been revealed that the anions have played important role in the assembly. In the case of 1 , the Yb3+ ions are completely encapsulated by two nma ligands with uncoordinated perchlorate anion balancing the positive charge. In the case of 2 , the Yb3+ ions are ligated by the ligand, oxygen atoms of the nitrate ion, and DMSO. Both complexes exhibit essential NIR luminescence of Yb3+ ions. 相似文献
86.
Dr. Peter Schweyen Martin Hoffmann Jens Krumsieck Dr. Benedikt Wolfram Dr. Xiulan Xie Prof. Dr. Martin Bröring 《Angewandte Chemie (International ed. in English)》2016,55(34):10118-10121
Zinc and cadmium complexes of meso‐arylisoporphyrins carrying a pyrrolyl or dipyrrinyl substituent at the sp3 carbon atom were obtained through a simple one‐pot variation of the Alder–Longo porphyrin synthesis. Key to the formation and stabilization of isoporphyrins is the presence of metal acetates during the oxidative macrocyclization step. The characteristic Q‐bands of isoporphyrins are found in the NIR region between 750 nm and 880 nm. All of the isolated pyrrolyl‐ and dipyrrinyl‐appended isoporphyrins are stable under typical laboratory conditions and allow chemical transformations like BF2 coordination, transmetalation, and ligand exchange. 相似文献
87.
The application of near-infrared (NIR) dyes (λ
em > 750 nm) to the analysis of biological samples shows much promise, because the long emission wavelengths of such dyes allow
interferences from biomolecule matrices to be minimized. In this paper, a novel NIR dye, 5,5′-dicarboxy-1,1′-disulfobutyl-3,3,3′,3′-tetramethylindotricarbocyanine
(DCDSTCY) has been developed for the spectrophotometric determination of total protein in serum. Under acidic conditions,
the binding of DCDSTCY to proteins caused a new peak at 878 nm, the height of which was proportional to the concentration
of protein. The linear range of the method was found to be 0.04–0.5 μg mL−1 for bovine serum albumin (BSA) and human serum albumin (HSA), and detection limits of 5 ng mL−1 were obtained for these substances. The maximum binding number of BSA with DCDSTCY was measured to be 133. The method proposed
here has been applied to the quantitation of total protein in serum, and recoveries of 96.6–104% were achieved.
Figure Near-infrared probe for protein determination 相似文献
88.
Application of two-dimensional near-infrared correlation spectroscopy to protein research 总被引:6,自引:0,他引:6
The purpose of the present paper is to demonstrate the potential of generalized two-dimensional (2D) near-infrared (NIR) correlation spectroscopy in studies of hydration and structure of proteins. We describe here two examples. The first example is concerned with heat denaturation process of ovalbumin in aqueous solutions and the second one deals with isomerizations with varying pH of serum albumin. New insight has been obtained into the hydration and unfolding process of secondary structures of ovalbumin and serum albumin by studying temperature- or pH-dependent correlation patterns in 2D synchronous and asynchronous spectra. Generalized 2D NIR correlation spectroscopy emphasizes spectral features not readily observable in conventional one-dimensional spectra, enabling to extract subtle but valuable structural changes concerning with the protein denaturation. 相似文献
89.
Marlon M. Reis Pedro H. H. Araújo Claudia Sayer Reinaldo Giudici 《Macromolecular rapid communications》2003,24(10):620-624
This work describes the estimation of polymer particle size from NIR spectra collected in situ and online in an automated reactor. A good linearity between spectra and average polymer particle diameter is found. The multivariate linear model is also tested with an independent data set not used in the model fitting. Despite varying monomer and polymer concentrations and temperature changes along the process, the average particle sizes are well predicted and can be monitored by NIR spectroscopy during emulsion polymerization reactions.
90.
Daniel Cozzolino 《Molecules (Basel, Switzerland)》2021,26(22)
Near infrared (NIR) spectroscopy is considered one of the main routine analytical methods used by the food industry. This technique is utilised to determine proximate chemical compositions (e.g., protein, dry matter, fat and fibre) of a wide range of food ingredients and products. Novel algorithms and new instrumentation are allowing the development of new applications of NIR spectroscopy in the field of food science and technology. Specifically, several studies have reported the use of NIR spectroscopy to evaluate or measure functional properties in both food ingredients and products in addition to their chemical composition. This mini-review highlights and discussed the applications, challenges and opportunities that NIR spectroscopy offers to target the quantification and measurement of food functionality in dairy and cereals. 相似文献