Molecular photoswitches have attracted much attention in biological and materials contexts. Despite the fact that existing classes of these highly interesting functional molecules have been heavily investigated and optimized, distinct obstacles and inherent limitations remain. Considerable synthetic efforts and complex structure property relationships render the development and exploitation of new photoswitch families difficult. Here, we focus our attention on acylhydrazones: a novel, yet underexploited class of photochromic molecules based on the imine structural motif. We optimized the synthesis of these potent photoswitches and prepared a library of over 40 compounds, bearing different substituents in all four crucial positions of the backbone fragment, and conducted a systematic study of their photochromic properties as a function of structural variation. This modular family of organic photoswitches offers a unique combination of properties and the compounds are easily prepared on large scales within hours, through an atom-economic synthesis, from commercially available starting materials. During our thorough spectroscopic investigations, we identified photoswitches covering a wide range of thermal half-lives of their (Z)-isomers, from short-lived T-type to thermally stable P-type derivatives. By proper substitution, excellent band separation between the absorbance maxima of (E)- and (Z)-isomers in the UV or visible region could be achieved. Our library furthermore includes notable examples of rare negative photochromic systems, and we show that acylhydrazones are highly fatigue resistant and exhibit good quantum yields.
Molecular photoswitches have attracted much attention in biological and materials contexts. Despite the fact that existing classes of these highly interesting functional molecules have been heavily investigated and optimized, distinct obstacles and inherent limitations remain. Considerable synthetic efforts and complex structure property relationships render the development and exploitation of new photoswitch families difficult. Here, we focus our attention on acylhydrazones: a novel, yet underexploited class of photochromic molecules based on the imine structural motif. We optimized the synthesis of these potent photoswitches and prepared a library of over 40 compounds, bearing different substituents in all four crucial positions of the backbone fragment, and conducted a systematic study of their photochromic properties as a function of structural variation. This modular family of organic photoswitches offers a unique combination of properties and the compounds are easily prepared on large scales within hours, through an atom-economic synthesis, from commercially available starting materials. During our thorough spectroscopic investigations, we identified photoswitches covering a wide range of thermal half-lives of their (Z)-isomers, from short-lived T-type to thermally stable P-type derivatives. By proper substitution, excellent band separation between the absorbance maxima of (E)- and (Z)-isomers in the UV or visible region could be achieved. Our library furthermore includes notable examples of rare negative photochromic systems, and we show that acylhydrazones are highly fatigue resistant and exhibit good quantum yields.
Synthesis, characterization and pharmacological evaluation of (E)-N′-(substituted-benzylidene)isonicotinohydrazide derivatives as potent anticonvulsant agents
作者:Manav Malhotra、Vikramdeep Monga、Sagun Sharma、Jainendra Jain、Abdul Samad、James Stables、Aakash Deep
DOI:10.1007/s00044-011-9739-5
日期:2012.9
also evaluated in the minimal clonic seizure model and exhibited potentanticonvulsant activity with lower neurotoxicity. Among all synthesized derivatives, analogue 3a was found to exhibit protection in MES and scPTZ seizure models. This study proved that isonicotinoyl hydrazides synthesized by condensing isoniazid with various aldehydes and ketones displayed moderate to potentanticonvulsant activity
Complexation studies of N′-[(1E)-1-phenylethylidene]isonicotinohydrazide: An aroylhydrazone Schiff base and lanthanides
作者:Yuimi Varam、Lonibala Rajkumari
DOI:10.1016/j.molliq.2016.11.098
日期:2017.2
constants of the complex formation equilibria which follow the order: Pr < Nd < Gd < Tb < Ho. The thermodynamic parameters (ΔG, ΔH, and ΔS) of protonation and complexation reactions are all negative suggesting the spontaneous, exothermic, of unfavorable entropy and enthalpy-driven reactions. Actual synthesis and characterization of Tb3 +-PHeH complex, confirmed the veracity of the complex formation equilibria
Structural insights into the hexamorphic system of an isoniazid derivative
作者:D. Hean、T. Gelbrich、U. J. Griesser、J. P. Michael、A. Lemmerer
DOI:10.1039/c5ce00275c
日期:——
The compound isonicotinic acid (E)-(1-phenylethylidene)hydrazide exists in 6 different structural forms isolated through complex manipulations on a Kofler hot stage.
Antimycobacterial compounds and method for making the same
申请人:Hearn Michael J.
公开号:US06846933B1
公开(公告)日:2005-01-25
The present invention relates to novel antimycobacterial compounds and in particular to antimycobacterial compounds comprised of Schiff base, diacylhydrazine, sulfur-containing diacylhydrazine and oxadiazoline congeners of isonicotinic acid hydrazide. This invention further relates to processes for their preparation, to intermediates useful in their preparation, to their use as therapeutic agents and to pharmaceutical compositions containing them.
A rubber composition prepared by compounding 0.05 to 20 parts by weight of at least one selected from substituted hydrazide compounds represented by the following Formulas (I) to (IV) per 100 parts by weight of a rubber component comprising at least one rubber selected from the group consisting of natural rubber and synthetic rubber, and a pneumatic tire using the same:
wherein A represents one selected from the group consisting of an aromatic group which may have a substituent, a hydantoin ring which may have a substituent, and a saturated or unsaturated linear hydrocarbon having 1 to 18 carbon atoms; Y represents hydrogen, an amino group, an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group, an alkenyl group, an aromatic group, a pyridyl group or hydrazino group; and R1 to R11 each represent hydrogen, an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group or an aromatic group.