Synthesis, characterization and catalytic oxidation of cyclohexene with molecular oxygen with host (nanopores of zeolite-Y)/guest (Ni(II) complexes of 14- and 16-membered tetraaza dioxo diphenyl macrocyclic ligands) nanocomposite materials

Ni(II) complexes of [14]aneN₄: 1,5,8,12-tetraaza-2,9-dioxo-4,11-diphenylcyclotetradecane; [16]aneN₄: 1,5,9,13-tetraaza-2,10-dioxo-4,12-diphenylcyclohexadecane; Bzo₂[14]aneN₄: dibenzo-1,5,8,12-tetraaza-2,9-dioxo-4,11-diphenylcyclotetradecane and Bzo₂[16]aneN₄: dibenzo-1,5,9,13-tetraaza-2,10-dioxo-4,12-diphenylcyclohexadecane have been encapsulated in the nanopores of zeolite-Y by a two-step process in the liquid phase: (i) adsorption of [bis(diamine)nickel(II)] (diamine = 1,2-diaminoethane, 1,3-diaminopropane, 1,2-diaminobenzene, 1,3-diaminobenzene); [Ni(N–N)₂]²⁺–NaY; in the nanopores of the zeolite-Y, and (ii) in situ condensation of the nickel(II) precursor complex with ethylcinnamate. The new host–guest nanocomposite materials (HGNM) were characterized by several techniques: chemical analysis and spectroscopic methods (FT-IR, UV/Vis, XRD and DRS) and the BET technique. These complexes were used for oxidation of cyclohexene with molecular oxygen.     

Host (nanopores of zeolite-Y)/guest (Co(II)-azamacrocyclic complexes) nanocomposite materials: synthesis,characterization and catalytic epoxidation of styrene with molecular oxygen

A series of Co(II) azamacrocyclic complexes, 12 Brunel, D, Bellocq, N, Sutra, P, Cauvel, A, Lasperas, M, Moreau, P, Di Renzo, F, Galarneau, A and Fajula, F. 1998. Coord. Chem. Rev., 178–180: 1085[Crossref], [Web of Science ®] , [Google Scholar]aneN₄, 14 De Vos, DE, Dams, M, Sels, BF and Jacobs, PA. 2002. Chem. Rev., 102: 3615[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]aneN₄, Bzo₂ 12 Brunel, D, Bellocq, N, Sutra, P, Cauvel, A, Lasperas, M, Moreau, P, Di Renzo, F, Galarneau, A and Fajula, F. 1998. Coord. Chem. Rev., 178–180: 1085[Crossref], [Web of Science ®] , [Google Scholar]aneN₄ and Bzo₂ 14 De Vos, DE, Dams, M, Sels, BF and Jacobs, PA. 2002. Chem. Rev., 102: 3615[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]aneN₄, have been encapsulated in the nanocavity of zeolite-Y by a one pot template condensation reaction. Co(II) complexes with azamacrocyclic ligands were entrapped in the nanocavity of zeolite-Y by a two-step process in the liquid phase: (i) adsorption of [bis(diamine)cobalt(II)], [Co(N–N)₂]-NaY, in the supercages of the zeolite, and (ii) in situ condensation of the cobalt(II) precursor complex with diethyloxalate. The new host/guest nanocomposite materials (HGNM) have been characterized by FTIR, DRS and UV-Vis spectroscopic techniques, XRD and elemental analysis, as well as nitrogen adsorption. These complexes (neat and HGNM) were used for epoxidation of styrene with O₂ as oxidant in different solvents. Electronic spectra of the reaction mixture indicated oxidation proceeds through a free radical mechanism.     

Host (nanopores of zeolite-Y)/guest (Ni(II)-tetraoxo dithia tetraaza macrocyclic complexes) nanocomposite materials: template synthesis and characterization

Nickel(II) complexes with six co-ordinate tetraoxo dithia tetraaza macrocyclic ligands derived from diamine and which provide a N₄S₂ co-ordination sphere, [18]aneN₄S₂: 1,4,10,13-tetraaza-5,9,14,18-tetraoxo-7,16-dithia-cyclooctadecane, [20]aneN₄S₂: 1,5,11,15-tetraaza-6,10,16,20-tetraoxo-8,18-dithia-cyclocosane, Bzo₂[18]aneN₄S₂: dibenzo-1,4,10,13-tetraaza-5,9,14,18-tetraoxo-7,16-dithia-cyclooctadecane, Bzo₂[20]aneN₄S₂: dibenzo-1,5,11,15-tetraaza-6,10,16,20-tetraoxo-8,18-dithia-cyclocosane, were entrapped in the nanopores of zeolite NaY by a two-step process in the liquid phase: (i) adsorption of [bis(diamine)nickel(II)] (diamine = 1,2-diaminoethane, 1,3-diaminopropane, 1,2-diaminobenzene, 1,3-diaminobenzene); [Ni(N–N)₂]²⁺-NaY; in the nanopores of the zeolite, and (ii) in situ template condensation of the nickel(II) precursor complex with thiodiglycolic acid. The mode of bonding and overall geometry of the complexes and new host/guest nanocomposite materials ([Ni([18]aneN₄S₂)]²⁺-NaY, [Ni([20]aneN₄S₂)]²⁺-NaY, [Ni(Bzo₂[18]aneN₄S₂)]²⁺-NaY, [Ni(Bzo₂[20]aneN₄S₂)²⁺-NaY) has been inferred through FT-IR, DRS and UV–vis spectroscopic techniques, molar conductance and magnetic moment data, XRD and elemental analysis, as well as nitrogen adsorption. An octahedral geometry around the nickel(II) ion is suggested for the complexes and new host/guest nanocomposite materials.     

Synthesis,characterization, and catalytic oxidation of ethylbenzene over host (zeolite-Y)/guest (copper(II) complexes of tetraaza macrocyclic ligands) nanocomposite materials

Cu(II) complexes of 14- and 16-membered tetraaza macrocyclic ligands have been encapsulated in nanopores of zeolite-Y by a two-step process in the liquid phase: (1) adsorption of [bis(diamine)copper(II)] (diamine = 1,2-diaminoethane, 1,3-diaminopropane, 1,2-diaminobenzene, and 1,3-diaminobenzene); [Cu(N–N)₂]²⁺–NaY; in the nanopores of the zeolite-Y and (2) in situ condensation of the copper(II) precursor complex with ethylcinnamate. The new host–guest nanocomposite materials were characterized by chemical analysis and spectroscopic methods. The “neat” and encapsulated complexes exhibit good catalytic activity in the oxidation of ethylbenzene at 333 K, using tert-butyl hydroperoxide as the oxidant. Acetophenone was the major product though small amounts of o- and p-hydroxyacetophenones were also formed revealing that C–H bond activation takes place both at benzylic and aromatic ring carbon atoms.     

Synthesis, characterization and catalytic oxidation of cyclohexene with molecular oxygen over host (zeolite-Y)/guest (nickel(II) complexes of R2[12]1,3-dieneN2O2 and R2[13]1,4-dieneN2O2; R = H, Me, Ph) nanocatalyst (HGN)

12- and 13-Membered diaza dioxa Schiff-base nickel(II) complexes were successfully prepared in a nanoscale microreactor by the template condensation of (1,8-diamino-3,6-dioxaoctane)nickel(II) complex with bifunctional diketones within the nanodimensional pores of zeolite Y. The host–guest nanocatalyst (HGN); ([Ni((R₂[12]1,3-dieneN₂O₂)]²⁺-NaY, [Ni(R₂[13]1,4-dieneN₂O₂)]²⁺-NaY; R = H, Me and Ph) is catalytically very efficient as compared to other neat complexes for oxidation of cyclohexene with molecular oxygen as oxidant in the absence of solvent at 70 °C, affording 2-cyclohexene-1-ol and 2-cyclohexene-1-one.     

Synthesis,characterization and catalytic oxidation of cyclohexene with molecular oxygen over host (nanopores of zeolite-Y)/guest ([Ni([R]2-N2X2)]2+ (R = H,CH3; X = NH,O, S) nanocatalyst

Nickel(II) complexes of 12-membered macrocyclic ligands with different donating atoms (N₂O₂, N₂S₂ and N₄) in the macrocyclic ring have been encapsulated in the nanocavity of zeolite-Y by the fexible-ligand method. Nickel(II) complexes with macrocyclic ligands were entrapped in the nanocavity of zeolite-Y by a two-step process in the liquid phase: (i) adsorption of precursor ligand; 1,2-di(o-aminophenyl-, amino, oxo, thio)ethane, N₂X₂; in the supercages of the Ni(II)–NaY, and (ii) in situ condensation of the Ni(II) precursor complex; [Ni(N₂X₂)]²⁺; with glyoxal or biacetyl. The new host–guest nanocatalysts (HGNM), [Ni([R]₂-N₂X₂)]²⁺–NaY (R = H, CH₃; X = NH, O, S), have been characterized by FT-IR, DRS and UV–Vis spectroscopic techniques, XRD and elemental analysis, as well as nitrogen adsorption, and were used for oxidation of cyclohexene with molecular oxygen.     

Epoxidation of cyclooctene by host (nanocavity of zeolite-Y) guest (copper(II) complexes with 16- and 17-membered diaza dioxa macrocyclic Schiff bases) nanocomposite materials

This work reports the synthesis and characterization of macrocyclic copper(II) complexes encapsulated within the nanopores of zeolite-Y. The obtained nanoparticles entrapped in the nanopores of zeolite have been characterized by FT-IR, UV–Vis, Diffuse reflectance spectra, spectroscopic techniques, molar conductance, magnetic moment data, XRD, thermal, and elemental analysis. The complexes (neat and encapsulated) were used for the oxidation of cyclooctene with tert-butyl hydroperoxide as oxidant in different solvents. The supported Cu[L₁]²⁺-Y exhibited a moderate 81.9% selectivity for epoxidation with 84.2% conversion. The catalytic activity and selectivity of the heterogeneous catalysts do not change after recycling five times.     

Host (nanocavity of zeolite Y)/guest (Co(II), Ni(II) and Cu(II) complexes of unsaturated 16-membered octaaza; 3,4,11,12-tetramethyl-1,2,5,6,9,10,13,14-octaazacyclohexadecane; Me4[16]aneN8 nanocomposite materials (HGNM): template synthesis, characterization and catalytic oxidation of benzyl alcohol

Nanocavity zeolite-Y (host) encapsulated Co(II), Ni(II) and Cu(II) complexes of unsaturated 16-membered octaaza; 3,4,11,12-tetramethyl-1,2,5,6,9,10,13,14-octaazacyclohexadecane ‘Me₄[16]aneN₈’; macrocycle (guest) were synthesized and characterized by chemical analyses, s.e.m., x.r.d., u.v.–vis., d.r.s., surface area, pore volume, conductometric, magnetic measurements and i.r. spectroscopy with a view to confirming the encapsulation of complexes and to arrive at the composition, structure and geometry of encapsulated complexes. The characterization data show the absence of extraneous complexes, retention of zeolite crystaline structure and encapsulation in the nanocavities. Host–Guest Nanocomposite Materials (HGNM) ‘[M(Me₄[16]aneN₈)]²⁺-NaY’ are catalytically very efficient as compared to other neat complexes for the partial oxidation of benzyl alcohol which is stable and becomes recycled without much deterioration.     

Spectroscopic characterization of chromium(III), manganese(II) and nickel(II) complexes with a nitrogen donor tetradentate, 12-membered azamacrocyclic ligand

The complexes of Cr(III), Mn(II) and Ni(II) were synthesized with macrocyclic ligand i.e. 5,11-dimethyl-6,12-diethyl-dione-1,2,4,7,9,10-hexazacyclododeca -1,4,6,10-tetraene. The ligand (L) was prepared by [2+2] condensation reaction of 2,3-pentanedione and semicarbazide hydrochloride. These complexes were found to have the general composition [Cr(L)X(2)]X and [M(L)X(2)] (where M=Mn(II) and Ni(II); X=Cl(-), NO(3)(-), (1/2)SO(4)(2-), NCS(-) and L=ligand [N(6)]). The ligand and its transition metal complexes were characterized by the elemental analysis, molar conductance, magnetic susceptibility, mass, IR, electronic and EPR spectral studies. On the basis of IR, electronic and EPR spectral studies, an octahedral geometry has been assigned for these complexes except sulphato complexes which are of five coordinated geometry.     

Copper(II) complexes with 18-membered decaaza macrocycles: synthesis,characterization and catalytic activity

New square-planar copper(II) complexes of 18-membered decaaza macrocyclic ligands: 5,6,14,15-tetramethyl-1,3,4,7,8,10,12,13,16,17-decaazacyclooctadecane (Me₄[18]aneN₁₀); 1,10-dimethyl-(Me₂Me₄[18]aneN₁₀); 1,10-diethyl-(Et₂Me₄[18]aneN₁₀); 1,10-dipropyl-(Pr₂Me₄[18]aneN₁₀); 1,10-dibutyliso-(Bu₂Me₄[18]aneN₁₀) and 1,10-dibenzyl-5,6,14,15-tetramethyl-1,3,4,7,8,10,12,13,16,17-decaazacylooctadecane [(Benzyl)₂Me₄[18]aneN₁₀)] have been prepared by a one-pot template condensation of formaldehyde and 2,3-butanedihydrazone with alkyl and benzylamine in the presence of copper(II) ion. The complexes of the decaaza macrocycle have been characterized by elemental analyses, i.r., u.v.–vis., conductometric and magnetic measurements. The spectra of [Cu(R₂Me₄[18]ane N₁₀)](ClO₄)₂shows that the four nitrogen (α-diimine) atoms are coordinated to the copper(II) ion. These complexes are found to be effective catalysts for the selective oxidation of tetrahydrofuran to yield the corresponding tetrahydrofuran-2-one and a small amount of tetrahydrofuran-2-ol and 4-hydroxybutyraldehyde, using diluted H₂O₂ as the oxidant.     

Crown ether-appended Fe (III) porphyrin: Synthesis, characterization and catalytic oxidation of cyclohexene with molecular oxygen

A new crown ether appended Fe(Ⅲ) porphyrin complex was prepared by sulfuryl chloride appended benzo-15-crown-5 to the meso position of meso-5,10,15,20-tetra(4-hydrophenyl)porphyrin,and it was applied to catalytic oxidation of cyclohexene with molecular oxygen without reductant,showing a remarkable catalytic activity(conversion is up to 94%) and selectivity for 2-cyclohexen-1-ol(73%).     

Host (nanocavity of zeolite-Y)–guest (molybdophosphoric acid) nanocomposite materials: An efficient catalyst for solvent-free synthesis and deprotection of 1,l-diacetates

In the present work, a mild and efficient method has been developed for the synthesis of acylals from aldehydes with acetic anhydride in the presence of molybdophosphoric acid encapsulated into dealuminated zeolite Y (MPA-DAZY) as a catalyst under solvent-free conditions at 45–55 °C in good to excellent yield. The deprotection of acylals has also been attained using this catalyst in acetonitrile. The catalyst was reused several times without efficient loss of its catalytic activity.     

Oxovanadium(IV) and copper(II) complexes of 1,2-diaminocyclohexane based ligand encapsulated in zeolite-Y for the catalytic oxidation of styrene, cyclohexene and cyclohexane

N,N′-Bis(salicylidene)cyclohexane-1,2-diamine (H₂sal-dach) reacts with oxovanadium(IV) and copper(II) exchanged zeolite-Y in refluxing methanol to yield the corresponding zeolite-Y encapsulated metal complexes, abbreviated herein as [VO(sal-dach)]-Y and [Cu(sal-dach)]-Y. Spectroscopic studies (IR, electronic and ¹H NMR), thermal analysis, scanning electron micrographs (SEM) and X-ray diffraction patterns have been used to characterise these complexes. These encapsulated complexes catalyse the oxidation, by H₂O₂, of styrene, cyclohexene and cyclohexane efficiently in good yield. Under the optimized conditions, the oxidation of styrene catalysed by [VO(sal-dach)]-Y and [Cu(sal-dach)]-Y gave 94.6 and 21.7% conversion, respectively, where styreneoxide, benzaldehyde, benzoic acid, 1-phenylethane-1,2-diol and phenylacetaldehyde being the major products. Oxidation of cyclohexene catalysed by these complexes gave cyclohexeneoxide, 2-cyclohexene-1-ol, cyclohexane-1,2-diol and 2-cyclohexene-1-one as major products. Conversion of cyclohexene achieved was 86.6% with [VO(sal-dach)]-Y and 18.1% with [Cu(sal-dach)]-Y. A maximum of 78.1% conversion of cyclohexane catalysed by [Cu(sal-dach)]-Y and only 21.0% conversion by [VO(sal-dach)]-Y with major reaction products of cyclohexanone, cyclohexanol and cyclohexane-1,2-diol have been obtained.     

Template synthesis and characterization of diaza dioxa macrocyclic nanosized cobalt(II) complex dispersed within nanocavity of zeolite-Y

Nanocavity microreactor containing 15- and 16-membered diaza dioxa Schiff-base cobalt(II) complexes “[Co(Et[15]N₂O₂)]²⁺, [Co(Pr[16]N₂O₂)]²⁺, [Co(Ph[15]N₂O₂)]²⁺ and [Co(Ch[15]N₂O₂)]²⁺” have been prepared by the template synthesis of diamine (1,2-diaminoethane, 1,3-diaminopropane, 1,2-diaminobenzene or 1,2-diaminocyclohexane) with [(1,3-bis(2-carboxyaldehydephenoxy)propane)cobalt]²⁺;[Co(BCAPP)]²⁺@NaY within the pores of zeolite-Y. The nanosized cobalt(II) complex were entrapped in the supercage of Y-zeolite by a three-step process in the liquid phase: (i) exchange of Co(II) ions with NaY in water solution, (ii) reaction of Co(II)–NaY with excess BCAPP in methanol; [Co(BCAPP)]²⁺@NaY; (iii) template synthesis of [Co(BCAPP)]²⁺@NaY with diamine. The new nanosized complex entrapped in the nanocavity of zeolite Y was characterized by several techniques: chemical analysis and spectroscopic methods (FT-IR, UV–Vis, XRD, BET, DRS, XPS, TGA).     

Cobalt(II), nickel(II), and copper(II) complexes of 14-membered hexaazamacrocycles: synthesis and characterization

Cobalt(II), nickel(II), and copper(II) complexes containing 5,12-di(4-bromophenyl)-7,14-dimethyl-1,2,4,8,9,11-hexaazacyclotetradeca-7,14-diene-3,10-dione (H₂L¹) and 5,12-diphenyl-7,14-dimethyl-1,2,4,8,9,11-hexaazacyclotetradeca-7,14-diene-3,10-dione (H₂L²) have been synthesized. All complexes were characterized by elemental analysis, MALDI TOF-MS spectrometry, and electronic absorption spectroscopy. The crystal structures of two compounds, [Cu₂(H₂L¹)Cl₄]_n and [NiL²], were determined by X-ray powder diffraction. In the polymeric [Cu₂(H₂L¹)Cl₄]_n, the Cu₂Cl₄ units and H₂L¹ molecules are situated on inversion centers. Each Cu(II) has a distorted trigonal-bipyramidal coordination environment formed by N and O from H₂L¹ [Cu–N 2.340(14)?Å, Cu–O 1.952(11)?Å], two bridging chlorides [Cu–Cl 2.332(5), 2.279(5)?Å] and one terminal chloride [Cu–Cl 2.320(6)?Å]. In the [NiL²] complex, the Ni(II) situated on inversion center has a distorted square-planar coordination environment formed by four nitrogens from L² [Ni–N 1.860(11), 1.900(11)?Å].     

The preparation of a series of 12-, 13- and 14-membered tetra-imine macrocycles and characterization of their copper(II) complexes

Summary The 12-, 13- and 14-membered tetraphenyl substituted macrocycles Ph₄[12]TIM (2,3,8,9-tetraphenyl-1,4,7,10-tetra-azacyclododeca-1,3,7,9-tetraene), Ph₄[13]TIM (2,3,8,9-tetraphenyl-1,4,7,10-tetra-azacyclotrideca-1,3,7,9-tetraene) and Ph₄[14]TIM (2,3,9,10-tetraphenyl-1,4,8,11-tetradeca-1,3,8,10-tetraene) were prepared and their copper(II) complexes characterised. Magnetic and spectroscopic measurements (i.r. and u.v.-vis.) are discussed. A variety of macrocyclic precursers (KIM = 1,2,8,9-tetraphenyl-3, 7-diaza-2,7-dione) and KIM-dioxime were also prepared and characterised.     

Host (nanopores of zeolite-Y)/guest [manganese(II) with 12-membered tetradentate N2O2, N2S2 and N4 donor macrocyclic ligands] nanocatalysts: flexible ligand synthesis, characterization and catalytic activity

Mn(II) complexes of 12-membered macrocyclic ligands with three different donating atom sets (N₂O₂, N₂S₂ and N₄) in the macrocyclic ring have been encapsulated in the nanopores of zeolite-Y by the Flexible-Ligand Method (FLM). The complexes were entrapped in the nanocavity of zeolite-Y by a two-step process in the liquid phase: (i) adsorption of 1,2-di(o-aminophenyl-, amino, oxo, thio)ethane in the supercages of the zeolite and (ii) in situ condensation of the Mn(II) precursor complex ([Mn(N₂X₂)]²⁺) with glyoxal or biacetyl. The new host–guest nanocatalysts, [Mn([R]₂–N₂X₂)]²⁺–NaY (R = H, CH₃; X = NH, O, S), have been characterized by various physico-chemical methods. These complexes, both in their free states and as host–guest nanocatalysts, were used for oxidation of cyclohexene with tert-butylhydroperoxide (TBHP) oxidant in different solvents. Di-2-cyclohexenylether was identified as the main product. 2-Cyclohexene-1-one, 2-cyclohexene-1-ol and 1-(tert-butylperoxy)-2-cyclohexene were obtained as minor products. [Mn([H]₂–N₄)]²⁺–NaY was found to give the best reactivity and selectivity.     

Spectroscopic approach in characterization of chromium(III), manganese(II), iron(III) and copper(II) complexes with a nitrogen donor tetradentate, 14-membered azamacrocyclic ligand

The complexes of Cr(III), Mn(II), Fe(III) and Cu(II) were synthesized with the macrocyclic ligand i.e. 2,3,9,10-tetraketo-1,4,8,11-tetraazacyclotetradecane. The ligand was prepared by the [2 + 2] condensation reaction of diethyloxalate and 1,3-diamino propane. These complexes were found to have the general composition M(L)X3 and M'(L)X2 [where M = Mn(II) and Cu(II), M' = Cr(III) and Fe(III), L = ligand (N4) and X = Cl-, NO3-, 1/2SO4(2-) and [CH3COO-]. The ligand and its transition metal complexes were characterized by the elemental analyses, molar conductance, magnetic susceptibility, mass, IR, electronic, and EPR spectral studies. On the basis of IR, electronic and EPR spectral studies an octahedral geometry has been assigned for Cr(III), Mn(II) and Fe(III) and a tetragonal geometry for Cu(II) complexes.     

Template synthesis and characterization of host (nanopores of zeolite Y)/guest (Co(II)-tetraoxodithiatetraaza macrocyclic complexes) nanocomposite materials

A series of Co(II) tetraoxodithiatetraaza macrocyclic complexes ([18]aneN₄S₂, [20]aneN₄S₂, Bzo₂[18]aneN₄S₂ and Bzo₂[20]aneN₄S₂) have been encapsulated in the nanopores of zeolite Y by template condensation reaction. Co(II) complexes with tetraoxodithiatetraaza macrocyclic ligand were entrapped in the nanopores of zeolite Y by a two-steps process in the liquid phase: (i) ion-exchange of [bis(diamine)cobalt(II)] (diamine = 1,2-diaminoethane, 1,3-diaminopropane, 1,2-diaminobenzene, 1,3-diaminobenzene); [Co(N–N)₂]²⁺–NaY; in the nano-cavity of the zeolite, and (ii) in situ template condensation of the cobalt(II) precursor complex with thiodiglycolic acid. The mode of bonding and overall geometry of the complexes and new host/guest nanocomposite materials ([Co([18]aneN₄S₂)]²⁺–NaY, [Co([20]aneN₄S₂)]²⁺–NaY, [Co(Bzo₂[18]aneN₄S₂)]²⁺–NaY, [Co(Bzo₂[20]aneN₄S₂)²⁺–NaY) has been inferred through FT-IR, DRS and UV–Vis spectroscopic techniques, BET technique, molar conductance and magnetic moment data, XRD and elemental analysis, as well as nitrogen adsorption. The average number of encapsulated Co complexes per nano-cavity was determined to be 0.33 for the Co complexes–NaY. An octahedral geometry around the cobalt(II) ion is suggested for the complexes and new host/guest nanocomposite materials.