Month: November 2022

Photoregulation of Fluorescence in a Porphyrinic Dithienylethene Photochrome was written by Norsten, Tyler B.;Branda, Neil R.. And the article was included in Journal of the American Chemical Society in 2001.Reference of 57412-08-5 The following contents are mentioned in the article:

Synthesis and optical characterization was reported of a photochromic hybrid (I), where porphyrin macrocycles are attached to the ends of the 1,2-bis(3-thienyl)cyclopentene backbone. The relationship between the luminescence intensity of the porphyrins and the state of the photoswitch (open or closed) was clearly illustrated. The absorption spectrum of bis(porphyrin) I in the UV-vis region was essentially equivalent to the sum of the absorption spectra of the mol.’s components indicating that there was little change in the ground state of either chromophore upon covalent linking. Irradiation of I at 313 nm resulted in an immediate increase in the absorption intensity in the visible spectral region (500-625 nm) due to the appearance of the absorption bands of its closed isomer. After 4 min of continuous irradiation (2 x 10-4 M, toluene-d₈), the photostationary state was reached and was identified by ¹H NMR spectroscopy as consisting of 69% of the closed isomer. The ease at which this photochem. ring closure occurs was impressive in the light of the fact that porphyrins have been reported, on occasion, to inhibit photochromic processes. Irradiation of the closed isomer at ¦Ë >480 nm resulted in the rapid ring-opening photoreaction and e regeneration of the original absorption spectrum corresponding to I. Luminescence of the porphyrin macrocycles in I and its closed isomer greatly depended on the state of the 1,2-(dithienyl)cyclopentene photoswitch. In the open form it displayed significant fluorescence intensity at 655 nm when excited at 430 nm. When the photocyclization reaction was carried out by irradiating at 313 nm, the nonfluorescent closed form was produced. Back irradiation at ¦Ë >480 nm regenerated closed isomer I and restored the original emission spectrum. The intensity of the porphyrins fluorescence was conveniently regulated by toggling between open and closed isomers by alternate irradiation at 313 nm and >480 nm clearly demonstrating that I can act as a system for reversible data processing using fluorescence as the detection method. This study involved multiple reactions and reactants, such as 4-(10,15,20-Tri-p-tolylporphyrin-5-yl)phenol (cas: 57412-08-5Reference of 57412-08-5).

4-(10,15,20-Tri-p-tolylporphyrin-5-yl)phenol (cas: 57412-08-5) belongs to catalyst ligands. Attachment of the ligand to the metal may be through a single atom, in which case it is called a monodentate ligand, or through two or more atoms, in which case it is called a didentate or polydentate ligand. The ability of ligands to engender a variety of useful properties of organometallic complexes is the major enabling force for the discovery of new catalytic reactions, activation of small molecules, dramatically enhanced reactivity.Reference of 57412-08-5

Referemce:
Metal catalyst and ligand design,
Ligand Template Strategies for Catalyst Encapsulation – NCBI

Supramolecular Tetrad Featuring Covalently Linked Bis(porphyrin)-Phthalocyanine Coordinated to Fullerene: Construction and Photochemical Studies was written by Kc, Chandra B.;Lim, Gary N.;Karr, Paul A.;D’Souza, Francis. And the article was included in Chemistry – A European Journal in 2014.Reference of 57412-08-5 The following contents are mentioned in the article:

A multimodular donor-acceptor tetrad featuring a bis(zinc porphyrin)-(zinc phthalocyanine) ((ZnP-ZnP)-ZnPc) triad and bis-pyridine-functionalized fullerene was assembled by a “two-point” binding strategy, and investigated as a charge-separating photosynthetic antenna-reaction center mimic. The spectral and computational studies suggested that the mode of binding of the bis-pyridine-functionalized fullerene involves either one of the zinc porphyrin and zinc phthalocyanine (Pc) entities of the triad or both zinc porphyrin entities leaving ZnPc unbound. The binding constant evaluated by constructing a Benesi-Hildebrand plot by using the optical data was found to be 1.17¡Á10⁵ M^-1, whereas a plot of “mole-ratio” method revealed a 1:1 stoichiometry for the supramol. tetrad. The mode of binding was further supported by differential pulse voltammetry studies, in which redox modulation of both zinc porphyrin and zinc phthalocyanine entities was observed The geometry of the tetrad was deduced by B3LYP/6-31G* optimization, whereas the energy levels for different photochem. events was established by using data from the optical absorption and emission, and electrochem. studies. Excitation of the zinc porphyrin entity of the triad and tetrad revealed ultrafast singlet-singlet energy transfer to the appended zinc phthalocyanine. The estimated rate of energy transfer (k_ENT) in the case of the triad was found to be 7.5¡Á10¹¹ s^-1 in toluene and 6.3¡Á10¹¹ s^-1 in o-dichlorobenzene, resp. As was predicted from the energy levels, photoinduced electron transfer from the energy-transfer product, i.e., singlet-excited zinc phthalocyanine to fullerene was verified from the femtosecond-transient spectral studies, both in o-dichlorobenzene and toluene. Transient bands corresponding to ZnPc⁺ in the 850 nm range and C₆₀^– in the 1020 nm range were clearly observed The rate of charge separation, k_CS, and rate of charge recombination, k_CR, for the (ZnP-ZnP)-ZnPc⁺:Py₂C₆₀^– radical ion pair (from the time profile of 849 nm peak) were found to be 2.20¡Á10¹¹ and 6.10¡Á10⁸ s^-1 in toluene, and 6.82¡Á10¹¹ and 1.20¡Á10⁹ s^-1 in o-dichlorobenzene, resp. These results revealed efficient energy transfer followed by charge separation in the newly assembled supramol. tetrad. This study involved multiple reactions and reactants, such as 4-(10,15,20-Tri-p-tolylporphyrin-5-yl)phenol (cas: 57412-08-5Reference of 57412-08-5).

4-(10,15,20-Tri-p-tolylporphyrin-5-yl)phenol (cas: 57412-08-5) belongs to catalyst ligands. Attachment of the ligand to the metal may be through a single atom, in which case it is called a monodentate ligand, or through two or more atoms, in which case it is called a didentate or polydentate ligand. The ability of ligands to engender a variety of useful properties of organometallic complexes is the major enabling force for the discovery of new catalytic reactions, activation of small molecules, dramatically enhanced reactivity.Reference of 57412-08-5

Referemce:
Metal catalyst and ligand design,
Ligand Template Strategies for Catalyst Encapsulation – NCBI

Ultrasensitive gas phase detection of 2,4,6-trinitrotoluene by non-covalently functionalized graphene field effect transistors was written by Gajarushi, Ashwini S.;Surya, Sandeep G.;Walawalkar, Mrinalini G.;Ravikanth, M.;Rao, V. Ramgopal;Subramaniam, Chandramouli. And the article was included in Analyst (Cambridge, United Kingdom) in 2020.Safety of 4-(10,15,20-Tri-p-tolylporphyrin-5-yl)phenol The following contents are mentioned in the article:

The high energy d. (4.2 MJ kg^-1) and low vapor pressure (7.2 ¡Á 10^-9 atm) of chem. explosives such as TNT (2,4,6-trinitrotoluene) pose a grave security risk demanding immediate attention. Detection of such hazardous and highly challenging chems. demands specific, ultra-sensitive and rapid detection platforms that can concomitantly transduce the signal as an elec. readout. Although chemo-sensitive strategies have been investigated, the majority of them are restricted to detecting TNT from solutions and are therefore not implementable in real-time, on-field situations. Addressing this demand, we report an ultra-sensitive (parts-per-billion) and rapid (?40 s) detection platform for TNT based on non-covalently functionalized graphene field effect transistors (GFETs). This multi-parametric GFET detector exhibits a reliable and specific modulation in its Dirac point upon exposure to TNT in the vapor phase. The chem. specificity provided by 5-(4-hydroxyphenyl)-10,15,20-tri(p-tolyl) zinc porphyrin (ZnTTPOH) is synergistically combined with the high surface sensitivity of graphene through a non-covalent functionalization approach to realize p-doped GFETs (Zn-GFETs). Such a FET platform exhibits extremely sensitive shifts in Dirac point (¦¤D_P) that correlate with the number of nitro groups present in the analyte. Analytes with mono-, di-, and tri-nitro substituted aromatic mols. exhibit distinctly different ¦¤D_P, leading to unprecedented specificity towards TNT. Addnl., the Dirac point of Zn-GFETs is invariant for common and potential interferons such as acetone and 2-propanol (perfume emulsifiers) thereby validating their practical applicability. Furthermore, the ¦¤D_P is also manifested as changes in the contact potential of GFETs, indicating that sub-monolayer coverage of ZnTTPOH is sufficient to modulate the transfer characteristics of GFETs over an area 1000 times larger than the dopant dimensions. Specifically, ZnTTPOH-functionalized GFETs exhibit p-doped behavior with pos. ¦¤D_P with respect to pristine GFETs. Such p-doped Zn-GFETs undergo selective charge-transfer mediated interactions with TNT resulting in enhanced electron withdrawal from Zn-GFETs. Thus the ¦¤D_P shifts to a higher pos. gate voltage leading to the dichotomous combination of the highest signal generation (1.2 ¡Á 10¹² V mol^-1) with ppb level mol. sensitivity. Significantly, the signal generated due to TNT is 10⁵ times higher in magnitude compared to other potential interferons. The signal reliability is established in cross-sensitivity measurements carried out with a TNT-mDNB (1:10 molar ratio) mixture pointing to high specificity for immediate applications under atmospherically relevant conditions pertaining to homeland security and global safety. This study involved multiple reactions and reactants, such as 4-(10,15,20-Tri-p-tolylporphyrin-5-yl)phenol (cas: 57412-08-5Safety of 4-(10,15,20-Tri-p-tolylporphyrin-5-yl)phenol).

4-(10,15,20-Tri-p-tolylporphyrin-5-yl)phenol (cas: 57412-08-5) belongs to catalyst ligands. Catalytic transformations have become a mainstay in the toolkit of the synthetic and increasing non-synthetic chemist alike. And they often provide a convenient approach to fine-tuning the performance of known catalysts.Safety of 4-(10,15,20-Tri-p-tolylporphyrin-5-yl)phenol

Referemce:
Metal catalyst and ligand design,
Ligand Template Strategies for Catalyst Encapsulation – NCBI

Optically active macrocyclic cis-3 bis-adducts of C₆₀: regio- and stereoselective synthesis, exciton chirality coupling, and determination of the absolute configuration, and first observation of exciton coupling between fullerene chromophores in a chiral environment was written by Kessinger, Roland;Thilgen, Carlo;Mordasini, Tiziana;Diederich, Francois. And the article was included in Helvetica Chimica Acta in 2000.HPLC of Formula: 57412-08-5 The following contents are mentioned in the article:

A series of optically active cis-3 bis-adducts was obtained regio- and diastereoselectively by Bingel macrocyclization of C₆₀ with bis-malonates, which contain optically active tethers derived from 1,2-diols. The absolute configuration of the inherently chiral addition pattern in cis-3 bis-adducts had previously been determined by comparison of calculated and exptl. CD spectra. Full confirmation of these earlier assignments was now obtained by an independent method based on semiempirical AM1 and OM2 calculations combined with ¹H-NMR spectroscopy. It was found computationally that bis-malonates [RCH(O₂CCH₂CO₂Et)]₂, which contain (R,R)- or (S,S)-butane-2,3-diol derivatives as optically active tethers, preferentially form out-out cis-3 bis-adducts of C₆₀ as a single diastereoisomer in which the alkyl groups R adopt a gauche conformation, while the two glycolic H-atoms are in an antiperiplanar (ap) and the ester linkages to the fullerene in a gauche relationship. In contrast, in the less favorable diastereoisomer, which should not form, the alkyl groups R adopt an ap and the H-atoms a gauche conformation, while the ester bridges to the fullerene remain, for geometric reasons, locked in a gauche conformation. According to the OM2 calculations, the geometry of the fully staggered tether in the free bis-malonates closely resembles the conformation of the tether fragment in the bis-adducts formed. These computational predictions were confirmed exptl. by the measurement of the coupling constant between the vicinal glycolic H-atoms in the ¹H-NMR spectrum. This conformational anal. was further supported by the regio- and diastereoselective synthesis of cis-3 bis-adducts from bis-malonates, including tethers derived from cyclic glycol units with a fixed gauche conformation of the alkyl residues R at the glycolic C-atoms. Thus, a bis-malonate of (R,R)-cyclohexane-1,2-diol provided exclusively cis-3 bis-adduct. Incorporation of a tether derived from Me 4,6-O,O-benzylidene-¦Á-D-glucopyranoside into the bis-malonate and Bingel macrocyclization diastereoselectively produced the cis-3 stereoisomer as the only macrocyclic bis-adduct. If the geometry of the alkyl groups R at the glycolic C-atoms of the tether component deviates from a gauche relationship, as in the case of tethers derived from exo cis- and trans-norbornane-2,3-diol or from trans-cyclopentane-1,2-diol, hardly any macrocyclic product is formed. The absolute configurations of the various optically active cis-3 bis-adducts were also assigned by comparison of their CD spectra, which are dominated by the chiroptical contributions of the inherently chiral fullerene chromophore. A strong chiral exciton coupling was observed for optically active macrocyclic cis-3 bis-adducts of C₆₀ with two appended 4-(dimethylamino)benzoate or meso-tetraphenylporphyrin chromophores. Chiral exciton coupling between two fullerene chromophores was observed for the first time in the CD spectrum of the threitol-bridged bis-fullerene. This study involved multiple reactions and reactants, such as 4-(10,15,20-Tri-p-tolylporphyrin-5-yl)phenol (cas: 57412-08-5HPLC of Formula: 57412-08-5).

4-(10,15,20-Tri-p-tolylporphyrin-5-yl)phenol (cas: 57412-08-5) belongs to catalyst ligands. The atoms and molecules used as ligands are almost always those that are capable of functioning as the electron-pair donor in the electron-pair bond (a coordinate covalent bond) formed with the metal atom. Precious metals and metal oxides on carrier materials are used in many industrial processes as heterogenous catalysts.HPLC of Formula: 57412-08-5

Referemce:
Metal catalyst and ligand design,
Ligand Template Strategies for Catalyst Encapsulation – NCBI