OXIMES ARE OFTEN USED IN ORGANIC SYNTHESIS AS PROTECTED FORMS OF CARBONYL COMPOUNDS [1] OR AS CARBONYL DERIVATIVES FOR PURIFICATION AND CHARACTERIZATION PURPOSES [2]. ...

IN RECENT YEARS CONSIDERABLE EFFORT HAS BEEN DIRECTED TOWARDS THE TRANSITION METAL COMPLEX CATALYZED OXIDATION OF ORGANIC COMPOUNDS. AMONG THESE, DEOXIMATIONTO ALDEHYDES AND KETONES HAS SPECIALLY BEEN ATTENDED A LOT, SINCE CARBONYL COMPOUNDS ARE IMPORTANT INTERMEDIATES IN ORGANIC SYNTHESIS. ...

OXIMES ARE EXTENSIVELY USED FOR PURIFICATION AND CHARACTERIZATION OF CARBONYL COMPOUNDS AND IN THE PREPARATION OF AMIDES VIA THE BECKMANN REARRANGEMENT [1]. THEIR SYNTHESIS FROM NONCARBONYL COMPOUNDS [2] PROVIDES AN ALTERNATIVE PATHWAY TO ALDEHYDES AND KETONES. ...

BACKGROUND: TRANSITION METAL SCHIFF BASE COMPLEXES HAVE BEEN THE SUBJECT OF GROWING GREAT INTEREST DUE TO THEIR POTENTIAL APPLICATION IN DIFFERENT FIELDS OF BIOLOGICAL ACTIVITIES, MOLECULAR MAGNETIC MATERIALS AND METALLOSUPRAMOLECULAR CHEMISTRY [1].SCHIFF BASE LIGANDS HAVE GAINED MUCH IMPORTANCE IN MEDICINAL INORGANIC CHEMISTRY IN VIEW OF THEIR DIVERSE BIOLOGICAL, PHARMACO-LOGICAL, ANTITUMOR ACTIVITY AND THEIR EXCEPTIONAL CHELATING ABILITY [2]. MOLYBDENUM PLAY IMPORTANT ROLE IN BIOLOGICAL SYSTEMS. MOLYBDENUM COMPLEXE CHEMISTRY HAS GAINED MUCH ATTENTION SINCE MOLYBDENUM WAS FOUND IN THE ACTIVE SITES OF ENZYMES SUCH AS NITROGENASE, ALDEHYDE OXIDASE, XANTHINE OXIDASE, SULFITE OXIDASE, NITRATE REDUCTASE AND XANTHINE DEHYDROGENASE. MOREOVER, FOR POSSESSING ONE OR MORE MO=O UNIT IN THEIR ACTIVE SITES, THESE NATURAL OXOMOLYBDENUM ENZYMES ARE ALSO WIDELY USED AS CATALYSTS IN INDUSTRIAL PROCESSES SUCH AS OLEFIN METATHESIS, OLEFIN EPOXIDATION ETC. TO SIMULATE THE BIOLOGICAL ACTIVITIES, A NUMBER OF OXO-MOLYBDENUM COMPLEXES WITH STABLE AND VARIABLE OXIDATION STATES VARYING FROM FOUR TO EIGHT, HAVE BEEN INVESTIGATED. HOWEVER, IT IS STILL A CHALLENGE FOR PEOPLE TO UNDERSTAND WELL THAT THE IMPORTANT PROPERTIES OF THIS METAL AND ITS INTERACTION MECHANISM WITH LIVING ORGANISM. [3]METHODS: THE ASYMMETRIC TRIDENTATE SCHIFF BASE (H2L) WAS OBTAINED BY ADDITION OF A SOLUTION OF 2-AMINO-2- METHYLPROPAN-1-OL (0.01 MOL) IN ETHANOL TO A SOLUTION OF 2-HYDROXY-1-BEBZALDEHYDE (0.01 MOL) IN ETHANOL AND THE REACTION MIXTURE WAS STIRRED IN AIR AT REFLUX FOR 1 H. THE SOLUTION WAS KEPT ONE DAY GIVING A YELLOW PRECIPITATE. THE CRUDE PRODUCT WAS RECRYSTALLIZED FROM CHCL3. TO PREPARE NANO-SIZED [MOO2LCH3OH], A TETRAHYDROFURAN (THF) SOLUTION OF THE SCHIFF BASE LIGAND, H2L (5 MMOL) WAS POURED DROPWISE UNDER ULTRASONIC IRRADIATION INTO TO A [MOO2 (ACAC)2] (5MMOL) IN THF DURING 40 MIN. AFTER THE END OF THE TITRATION, THE SOLUTION WAS KEPT IN THE ULTRASONIC BATH FOR A PERIOD OF 120 MIN. THE OBTAINED PRECIPITATES WERE FILTERED AND THEN DRIED.RESULTS: NANOSTRUCTURES OF A NEW DIOXO MOLYBDENUM COMPLEX, [MOO2LCH3OH] HAVE BEEN SYNTHESIZED BY A SONOCHEMICAL PROCESS AND CHARACTERIZED BY SCANNING ELECTRON MICROSCOPY (SEM), X-RAY POWDER DIFFRACTION (XRD) AND FT-IR SPECTROSCOPY.CONCLUSION: SYNTHESIS OF A NEW NANO-SCALE DIOXIDOMOLYBDENUM (VI) COMPLEXES FROM 2-HYDROXY-1- BENZLALDEHYDE AND 2-AMINO-2-METHYL PROPANOL HAS BEEN PREPARED AND CHARACTERIZED.

MESOPOROUS MATERIALS POSSESS LARGE SURFACE AREA AND UNIFORM PORE SIZE AND ARE ADVANTAGEOUS AS A CATALYTIC SUPPORT COMPARED TO MICROPOROUS MOLECULAR SIEVES. RECENTLY, RESEARCHERS HAVE PAID MORE ATTENTION TO SBA-16 MESOPOROUS MATERIAL BECAUSE OF ITS WELL DEFINED PORE SIZE, HIGH THERMAL STABILITY, AND, ESPECIALLY, THREE DIMENSIONAL CHANNEL CONNECTIVITY, WHICH WOULD PROVIDE FAVORABLE MASS TRANSFER KINETICS [1-5]. IT HAS A 3D CUBIC ARRANGEMENT OF MESOPORES CORRESPONDING TO THE IM3M SPACE GROUP.IN THIS STUDY, A MOLYBDENUM-SCHIFF BASE COMPLEX WAS ENCAPSULATED ONTO THE PORES OF MESOPOROUS SBA-16. FIRST, SBA-16 MESOPOROUS SILICA WAS SYNTHESIZED UNDER REFLUX CONDITION USING BLOCK COPOLYMER POLY(ETHYLENE OXIDE-POLY(PROPYLENE OXIDE)-POLY(ETHYLENE OXIDE) (F127) AS SURFACTANT, CETYLTRIMETHYLAMMONIUM BROMID (CTAB) AS CO-SURFACTANT, AND TETRAETHYL ORTHOSILICATE (TEOS) AS SILICA SOURCE. THEN, MOLYBDENUM-SCHIFF BASE COMPLEX WAS SYNTHESIZED IN THE MESOPOROUS CAGE OF SBA-16 THROUGH THE ―ENCAPSULATION‖ METHOD. THE PORE ENTRANCE SIZE OF MESOPOROUS SBA-16 WAS MODIFIED BY SILYLATION TO TRAP MOLYBDENUM-SCHIFF BASE COMPLEX IN THE CAGE. CHARACTERIZATION OF THE RESULTED HETEROGENEOUS CATALYST WAS PERFORMED WITH DIFFERENT PHYSICOCHEMICAL TECHNIQUES SUCH AS INFRARED SPECTROSCOPY (FT-IR), X-RAY DIFFRACTION (XRD), TRANSMISSION ELECTRON MICROSCOPY (TEM), INDUCTIVELY COUPLED PLASMA (ICP), SCANNING ELECTRON MICROSCOPY (SEM), NITROGEN ADSORPTION-DESORPTION ANALYSIS (BET) AND SOLID-STATE UV-VIS SPECTROSCOPY. THE CATALYTIC ACTIVITY OF THE PREPARED CATALYST WAS INVESTIGATED IN THE EPOXIDATION OF OLEFINS IN THE PRESENCE OF CUMENE HYDROPEROXIDE AS OXIDANT AND 1,2-DICHLOROETHANE AS SOLVENT. THE RESULTS SHOWED THAT THE OBTAINED HETEROGENEOUS CATALYST HAS HIGH CATALYTIC ACTIVITY AND CAN BE RECYCLED AT LEAST TWO TIMES WITHOUT CONSIDERABLE DECREASE IN ACTIVITIES.

ALDEHYDES AND KETONES REPRESENT AN IMPORTANT CLASS OF PRODUCTS AND INTERMEDIATES IN THE FINE CHEMICALS AND SPECIALTIES[1]. THE OXIDATION OF ALCOHOLS TO CARBONYL COMPOUNDS IS AN IMPORTANT TRANSFORMATION OF ORGANIC SYNTHESIS, AND SEVERAL METHODS HAVE BEEN EXPLORED TO ACCOMPLISH SUCH A CONVERSION [2]. ...

OXIDATION OF ALCOHOLS TO ALDEHYDES AND KETONES IS ONE OF THE MOST IMPORTANT TRANSFORMATIONS IN ORGANIC SYNTHESIS. IN PARTICULAR THE OXIDATION OF PRIMARY ALCOHOLS TO ALDEHYDE IS IMPORTANT SINCE THEY FIND WIDE APPLICATIONS AS INTERMEDIATES ARE FINE CHEMICALS PARTICULARY FOR PERFUME INDUSTRY...

A NEW SCHIFF BASE LIGAND AND ITS COPPER(II) COMPLEX HAVE BEEN SYNTHESIZED BY THE REACTION OF THE NEW TETRADENTATE SCHIFF BASE LIGAND WITH COPPER(II) ACETATE IN 1:1 MOLAR RATIO. IN THIS COMPLEX, THE LIGAND WAS COORDINATED TO THE METALS VIA THE IMINE NITROGEN AND SULFUR ATOMS. THE COMPLEX HAVE BEEN FOUND TO POSSESS 1:1 METAL TO LIGAND STOICHIOMETRY AND THE MOLAR CONDUCTANCE DATA REVEALED THAT THE METAL COMPLEX WERE NON-ELECTROLYTE. THE SCHIFF BASE AND ITS COMPLEX HAVE BEEN CHARACTERIZED BY FT-IR, 1H NMR, UV/VIS, ELEMENTAL ANALYSIS AND CONDUCTOMETRY. ELECTROCHEMICAL PROPERTIES OF THE LIGAND AND ITS METAL COMPLEX WERE ALSO INVESTIGATED IN DMSO SOLVENT AT THE 100 MVS−1 SCAN RATE. THE LIGAND AND ITS COPPER COMPLEX SHOWED BOTH QUASI-REVERSIBLE AND IRREVERSIBLE PROCESSES AT THIS SCAN RATE. ...