Host (nanocavity of zeolite-Y)/guest (Mn(II), Co(II), Ni(II) and Cu(II) complexes of pentadendate Schiff-base ligand) nanocomposite materials (HGNM): application in the heterogeneous oxidation of cyclohexene

Transition metal (M = Mn(II), Co(II), Ni(II) and Cu(II)) complexes with pentadendate Schiff-base ligand; N,N′-bis(salicylidene)-2,6-pyridinediaminato, H₂ [sal-2,6-py]; was entrapped in the nanocavity of zeolite-Y by a two-step process in the liquid phase: (i) adsorption of bis(salicylaldiminato)metal(II); [M(sal)₂]-NaY; in the supercages of the zeolite, and (ii) in situ Schiff condensation of the metal(II) precursor complex with the corresponding 2,6-pyridinediamine; [M(sal-2,6-py)]-NaY. The new materials were characterised by several techniques: chemical analysis, spectroscopic methods (DRS, BET, FTIR and UV/Vis), conductometric and magnetic measurements. Analysis of the data indicates that the M(II) complexes are encapsulated in the nanodimensional pores of zeolite-Y and exhibit different from those of the free complexes, which can arise from distortions caused by steric effects due to the presence of sodium cations, or from interactions with the zeolite matrix. The Host–Guest Nanocomposite Materials (HGNM); [M(sal-2,6-py)]-NaY; catalyzes the oxidation of cyclohexene with tert-butylhydroperoxide (TBHP). Oxidation of cyclohexene with HGNM gave 2-cyclohexene-1-one, 2-cyclohexene-1-ol and 1-(tert-butylperoxy)-2-cyclohexene. [Mn(sal-2,6-py)]-NaY shows significantly higher catalytic activity than other catalysts.     

Alumina-supported Mn(II), Co(II), Ni(II) and Cu(II) N,N-bis(salicylidene)-2,2-dimethylpropane-1,3-diamine complexes: Synthesis, characterization and catalytic oxidation of cyclohexene with tert-butylhydroperoxide and hydrogen peroxide

New square-planar manganese(II), copper(II), nickel(II) and cobalt(II) complexes of a tetradentate Schiff-base ligand “N,N-bis(salicylidene)-2,2-dimethylpropane-1,3-diamine, H₂[salpnMe₂]” have been prepared and characterized by elemental analyses, IR, UV–Vis, conductometric and magnetic measurements. The results suggest that the symmetrical Schiff-base is a bivalent anion with tetradentate N₂O₂ donors derived from the phenolic oxygen and azomethine nitrogen. The formulae was found to be [M(salpnMe₂)] for the 1:1 non-electrolytic complexes. Alumina-supported metal complexes (ASMC; [M(salpnMe₂)/Al₂O₃]) catalyze the oxidation of cyclohexene with tert-buthylhydroperoxide (TBHP) and hydrogen peroxide. Oxidation of cyclohexene with TBHP gave 2-cyclohexene-1-one, 2-cyclohexene-1-ol and 1-(tert-butylperoxy)-2-cyclohexene whereas, oxidation with H₂O₂ resulted in the formation of cyclohexene oxide and cyclohexene-1,2-diol. Manganese(II) complex supported on alumina “[Mn(salpnMe₂]–Al₂O₃” shows significantly higher catalytic activity than other catalysts.     

Synthesis and characterization of alumina-supported Mn(II), Co(II), Ni(II) and Cu(II) complexes of bis(salicylaldiminato)hydrazone as catalysts for oxidation of cyclohexene with tert-buthylhydroperoxide

Complexes of type [M(SAH)(OH₂)], where M is Mn(II),Co(II),Ni(II) and Cu(II), and SAH is the Schiff-base formed by condensation of salicylaldehyde (2 equiv.) and hydrazine (1 equiv.), bis(salicylaldiminato)hydrazone, or “2-({(z)-2-[(E)-1-(2-hydroxyphenyl)methylidene]hydrazono}methyl)phenol” have been prepared and characterized by elemental analysis, IR, UV–vis spectroscopy, conductometric, small area X-ray photoelectron spectroscopy and magnetic measurements. Elemental analysis suggests the stoichiometry to be 1:1 (metal:ligand). The results indicate that the Schiff-base ligand coordinates through one azomethine nitrogen and two phenolic oxygen to the metal ions. Conductance measurements suggest the non-electrolytic nature of the complexes. The atomic concentration of the complexes showed the ratio of M:N:O = 1:2:3, that indicates that a water molecule was in the complex. Alumina-supported complexes “[M(SAH)OH₂]-Al₂O₃” catalyze the oxidation of cyclohexene with tert-butylhydroperoxide (TBHP). The major products of the reaction were 2-cyclohexene-1-ol, 2-cyclohexene-1-one and 2-cyclohexene-1-(tert-butylperoxy). The influence of solvent on the oxidation reaction has been studied. [M(SAH)OH₂]-Al₂O₃ shows significantly higher catalytic activity than other alumina-supported complexes. These catalysts can also be reused in the oxidation of cyclohexene several times. The new materials “[M(SAH)OH₂]-Al₂O₃” were characterized by several techniques: chemical analysis and spectroscopic methods (FT-IR, UV–vis, XRD, DRS).     

大环双核Cu(Ⅱ)催化剂的制备及催化性能

合成了大环双核铜(Ⅱ)催化剂—{[Cu(Ⅱ)aneN5]2(DDS)}(ClO4)4,用元素分析和红外光谱对其结构进行了表征。常压条件下,以制得的催化剂催化分子氧氧化环己烯合成环己烯酮,考察了催化剂用量、反应时间、反应温度、溶剂用量等因素对环己烯酮合成的影响。优化得到较佳合成工艺条件为:O2流速大约5 mL/min,以环己烯4 mL计,催化剂2 mg,反应时间12 h,反应温度338 K,乙腈12 mL。环己烯的转化率为65.9%,环己烯酮的选择性为78.3%。     

One-Dimensional Ni(II) and Cu(II) Coordination Polymers Containing Syn-Syn Thiophene-2,5-dicarboxylate and Propane-1,3-diamine

New thiophene-2,5-dicarboxylate complexes with the formula of [M(μ-tdc)(pen)₂] _n (M = Ni(II) (1) and Cu(II) (2), pen = propane-1,3-diamine, tdc = thiophene-2,5-dicarboxylate) have been synthesized and characterized by using thermal (TG/DTG, DTA and MS) analysis, IR and UV–Vis. spectroscopies, magnetic measurement and single crystal X-Ray diffraction techniques. The Ni(II) and Cu(II) ions are distorted octahedrally coordinated by two oxygen atoms of two bridging thiophene-2,5-dicarboxylate ligands and four nitrogen atoms of the trans-pen ligands. The polymeric chains are connected together by hydrogen bonds interactions, forming three-dimensional network.     

Synthesis and Characterization of Zinc(II) Oxide Nanoparticles by Thermal Decomposition of Two Zinc(II) Nitrite Coordination Polymer Precursors

Two zinc(II) coordination polymers, {[Zn(3-bpdb)(NO₂)]·0.5H₂O} _n (1) and [Zn(4-bpdb)(NO₂)₂] _n (2), 3-bpdb = 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene and 4-bpdb = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene}, have been synthesized and characterized by elemental analyses and IR spectroscopy. Nanoparticles of zinc(II) oxide have been prepared by thermolyses of two different zinc(II) coordination polymers, 1–2. The nano-materials were characterized by scanning electron microscopy, X-ray powder diffraction and IR spectroscopy. The thermal stability of ZnO nano-particles was studied by thermal gravimetric and differential thermal analysis and showed that there is no loss of weight, which indicates that the products were zinc(II) oxide. This study demonstrates the coordination polymers may be suitable precursors for the preparation of nanoscale materials.     

Chromium modified silica from rice husk as an oxidative catalyst

RH-Cr and RH-Cr500 were synthesized from rice husk by solvent extraction and gel precipitation technique. The specific surface area of RH-Cr and RH-Cr500 were found to be 0.542 and 1.20 m² g⁻¹ respectively. Energy dispersive X-ray (EDX) analysis showed that Cr(III) was homogenously incorporated in the matrix of both samples to a maximum of ca. 16% in RH-Cr500. Elemental analysis showed that RH-Cr contained ca. 15% carbon, while RH-Cr500 contained negligible amounts. FTIR analysis showed the extracted solid contained silanol (Si–OH) and siloxane (Si–O–Si) groups. Catalytic oxidation of cyclohexane with H₂O₂ using RH-Cr as the catalyst showed a 27.13% conversion to cyclohexanone and cyclohexanol with a selectivity of 57.37% and 42.63% respectively. However, RH-Cr500 showed only 14.01% conversion but with a selectivity of 64.83% of cyclohexanone and 35.17% of cyclohexanol. Epoxidation of cyclohexene using H₂O₂ with RH-Cr as the catalyst gave a conversion rate of 30.17% with a selectivity of 11.51% towards cyclohexene oxide, 63.21% 2-cyclohexen-1-one and 25.29% 2-cyclohexen-1-ol. The same reaction with RH-Cr500 as the catalyst showed 21.28% conversion with 14.65% cyclohexene oxide, 68.71% 2-cyclohexen-1-one and 16.64% 2-cyclohexen-1-ol. In the catalytic oxidation of cyclohexanol to cyclohexanone, RH-Cr showed a conversion of 12.25% while RH-Cr500 showed a conversion of 13.52%. No others products were detected in the conversion. Comparison with published catalytic systems showed that RH-Cr and RH-Cr500 to be a better catalyst even though the surface area of these catalysts were low.     

Interesting Copper(I) and Mercury(II) 1D Coordination Polymers Based on 3,6-Bis(2-pyridylthio)pyridazine Ligand: Syntheses,Structures and Properties

Two interesting d¹⁰ metal complexes of 3,6-bis(2-pyridylthio)pyridazine ligand (PTP), [Cu₃I₃(PTP)] _n (1) and [HgI₂(PTP)] _n (2), have been synthesized and characterized by IR, elemental analysis, UV–Vis–NIR spectra, thermal analysis and single crystal X-ray diffraction analysis. Single-crystal X-ray analyses show that two complexes are both 1D chain coordination polymer. Complex 1 is a linear chain structure which is constructed from trinuclear Cu₃I₃ butterfly-shaped units by means of Cu–I bonds. Complex 2 is one-dimensional helical chain structure. In complex 2, two helical single chains form a double helix structure, and these double helix structures are further assembled to form a quasi 2D network by C–H⋯I hydrogen bonds. Optical diffuse-reflection spectra results suggest complex 1 has the property of the semiconductor.     

One-Dimensional Cobalt(II) and Zinc(II) Succinato Coordination Polymers with Nicotinamide: Synthesis, Structural, Spectroscopic, Fluorescent and Thermal Properties

Cobalt(II) and zinc(II) succinato (suc) coordination polymers with nicotinamide (nia), {[Co(μ-suc)(H₂O)₂(nia)₂] · 2H₂O} _n (1) and {[Zn(μ-suc)(H₂O)₂(nia)₂] · 2H₂O} _n (2) have been synthesized and characterized by elemental analyses, magnetic moments, IR and TG-DTA. Single-crystal X-ray analyses of 1 and 2 reveal that these complexes are isostructural and crystallize in triclinic space group Complexes 1 and 2 are 1-D coordination polymers, in which the metal(II) ions exhibit an octahedral geometry with two suc, two nia and two aqua ligands. The nia ligand is N-bonded, while the suc ligand bridges the metal centers through the carboxylate groups. The 1D chains are further assembled to form 3D networks by strong N–H···O and OW–H···O hydrogen bonds. IR spectra confirm the coordination modes of both suc and nia ligands, while TG-DTA data are in agreement with the crystal structures. Fluorescent analysis in the solid state shows that all complexes display intraligand (π–π*) emissions of nia.     

Preparation of Cadmium(II) Oxide Nanoparticles from a New One-Dimensional Cadmium(II) Coordination Polymer Precursor; Spectroscopic and Thermal Analysis Studies

A one-dimensional Cd(II) coordination polymer containing 2-pyridinecarboxylate (2-pyc⁻) and iodide anions [Cd(μ-2-pyc)(μ-I)] _n (1), is synthesized and characterized by elemental analysis, IR spectroscopy, thermal analysis and X-ray crystallography. The single-crystal X-ray data show that the coordination number for the Cd²⁺ ion is five. The thermal stability of 1 was studied by thermogravimetry and differential thermal analyzes. Cd(II)O nanoparticles were prepared by direct calcination of 1 at different temperatures. The Cd(II)O nanoparticles were characterized by X-ray powder diffraction and scanning electron microscopy. The results show that the morphology of the Cd(II)O nanoparticles is dependent upon the thermolysis temperature.     

Cobalt(II), Zinc(II) and Cadmium(II)-Squarate Complexes with N-Methylimidazole

Three M(II)-squarate complexes, [Co(sq)(H₂O)(Nmim)₄] (1), [Zn(μ_1,3-sq)(H₂O)₂ (Nmim)₂] _n (2) and [Cd(μ_1,3-sq)(H₂O)₂(Nmim)₂] _n (3) (sq = squarate, Nmim = N-methylimidazole) have been synthesized and characterized by elemental, spectral (IR and UV–Vis.) and thermal analyses. The molecular structures of the complexes have been investigated by single crystal X-ray diffraction technique. The squarate ligand acts as two different coordination modes as a monodentate (in 1) and bis(monodentate) (O ^1– O ³ ) bridging ligand (in 2, 3). The Co(II) atom has a distorted octahedral geometry with the basal plane comprised of three nitrogen atoms of Nmim ligands and a oxygen atom of squarate ligand. The axial position is occupied by a nitrogen atom of Nmim and one aqua ligand. The crystallographic analysis reveals that the crystal structures of 2 and 3 are one-dimensional linear chain polymers along the c and b axis, respectively. The configuration around each metal(II) ions are distorted octahedral geometry with two nitrogen atoms of trans-Nmim, two aqua ligands and two oxygen atoms of squarate-O¹,O³ ligand. These chains are held together by the C–H···π, π···π and hydrogen-bonding interactions, forming three-dimensional network.     

Copper (II) Ions into Polyphosphazenes: Solid-Like Solution Behavior

Reaction of Cu(BF₄)₂ salt with the polymer [NP(OC₆H₄C(O)C–OC₆H₅)₂] _n (1) in THF affords three new polymers gels containing varied copper (II) ions contents, (2), (3), and (4). The nature of the copper (II) ions in the gel (2)–(4) was examined by IR spectroscopy, solid state ³¹P, ¹³C and ⁶³Cu NMR spectroscopy and EPR spectroscopy. Despite the copper content, the gels were insulators as measured by complex impedance spectroscopy. SEM images show a uniform distribution of the Cu (II) ions and a most porous morphology than those without copper polymer. TEM images show the formation of small aggregates being smallest for, gel (2) of about 200 nm. All the data suggest the Cu²⁺ centers behave as a solid dilute into the polyphosphazenes.     

Synthesis, characterization of high Ti-containing Ti-MCM-41 catalysts and their activity evaluation in oxidation of cyclohexene and epoxidation of higher olefins

A series of titanium rich isomorphous substituted Ti MCM-41 and HMS materials have been synthesized with different Si/Ti ratios. The highest amount of Ti incorporated in synthesis gel is in TiMCM-41 (Si/Ti = 10). Whereas for TiHMS catalysts, Ti is incorporated up to Si/Ti = 50 successfully without forming any extra framework TiO₂. Cyclohexene epoxidation reaction with dry tert-butyl hydroperoxide (TBHP) as an oxidant has been studied to evaluate the catalytic properties of Ti substituted mesoporous catalysts. The effect of molar ratio of substrate:oxidant in this reaction has been studied and high conversion, high selectivity were achieved at 2: 1 molar ratio with TiMCM-41 (Si/Ti =25). Dry TBHP (in dichloromethane) and chloroform were found as good oxidant and solvent system for this reaction. Pure siliceous mesoporous silica and low `Ti' substituted mesoporous silicas were found to be efficient catalysts for oxidation of cyclohexene. An interesting variation of the selectivity from allylic oxidation to epoxidation during oxidation of cyclohexene was observed with an increase in the Ti amount in the mesoporous framework. The allylic oxidation of cyclohexene has been carried out using molecular oxygen as an oxidant and in the presence of a small amount of TBHP as initiator. Siliceous HMS materials gave better conversion compared to MCM-41 type of materials and other conventional silicas like silica gel, fumed silica etc. in allylic oxidation of cyclohexene. Epoxidation of higher cyclic olefins like cyclooctene, cyclododecene, cis-cyclododecene and linear olefins 1-Heptene, cis-2-hexene, 1-undecene was carried out over TiMCM-41 (Si/Ti = 25). Ti substituted mesoporous catalysts were characterized by elemental analysis, XRD, FTIR, UVDRS, ²⁹SiMASNMR, BET surface area and pore size distribution techniques.     

锡卟啉的合成及其绿色催化氧气氧化环己烯

考察催化剂金属锡次卟啉二甲酯催化氧化环己烯的反应性能。探讨了在催化氧化过程中,反应温度、压力、时间、催化剂用量等因素对环己烯转化率和产物选择性的影响,并结合GC-MS在线分析检测。结果表明,当温度100℃、压力0.8 MPa、时间7 h、催化剂用量0.5 mg(7.6×10-4mmol)、环己烯10 mL(98 mmol)的条件下,环己烯的转化率达84%,相应产物2-环己烯-1-醇和2-环己烯-1-酮的总选择性为94%,并对该反应的催化氧化反应机理进行了初步研究。     

Ti-containing MCM-41 catalysts for liquid phase oxidation of cyclohexene with aqueous H2O2 and tert-butyl hydroperoxide

Framework Ti-substituted and Ti-grafted MCM-41 mesoporous material has been prepared by direct hydrothermal synthesis and a post-synthesis grafting method. The materials have been tested as catalysts for cyclohexene oxidation with aqueous H₂O₂ and tert-butyl hydroperoxide (TBHP). With aqueous H₂O₂ in methanol, the major products were cyclohexene diol and its methyl ethers. No cyclohexene oxide was produced. Titanium leaching was a serious problem, and the catalyst lost its activity irreversibly after only one cycle of reaction. With TBHP, the selectivity for cyclohexene oxide was near 100%, titanium leaching was negligible, and the catalyst could be repeatedly used after regeneration without suffering significant activity loss. However, the reaction rate was lower than when H₂O₂ was used. Framework substituted material and catalysts prepared by Ti-grafting onto a MCM-41 support behaved similar, but the Ti-grafted MCM-41 is somewhat more active. The turnover frequency (TOF) per mole of Ti decreases with an increase of Ti content in the catalyst. This is caused by a reduced Ti dispersion within the silica matrix. This revised version was published online in July 2006 with corrections to the Cover Date.     

Methane Oxidation Over M–8YSZ and M–CeO2/8YSZ (M = Ni, Cu, Co, Ag) Catalysts

The oxidation of methane has been studied by sequential flow reaction experiments over M–8YSZ and M–CeO₂/8YSZ (M=Ni, Cu, Co, Ag) catalysts as a function of CH₄/O₂ from 773 to 1073 K. Over Ni–8YSZ and Ni–CeO₂/8YSZ, methane pyrolysis is dominant leading to surface carbon formation at temperatures of 873 K and above. While the addition of ceria to Ni–8YSZ to produce Ni–CeO₂/8YSZ does not significantly affect the reaction kinetics, the activity of Cu–CeO₂/8YSZ, Co–CeO₂/8YSZ, and Ag–CeO₂/8YSZ are higher than their M–8YSZ counterparts. The activity of Co–CeO₂/8YSZ at high temperatures (973 K and above) is higher than Ni-8YSZ with selectivity towards partial methane oxidation and CO formation. Considering Ni-based catalysts are prone to deactivation due to surface carbon accumulation, Co–CeO₂/8YSZ, Cu–CeO₂/8YSZ, and Ag–CeO₂/8YSZ are possible alternative anode cermets for direct hydrocarbon oxidation solid-oxide fuel cells (SOFC).     

Synthesis and Characterization of One-Dimensional Zinc(II) Coordination Polymers as Precursors for Preparation of ZnO Nanoparticles via Thermal Decomposition

Two new Zn(II) coordination polymers from the ligand, 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene (bpdh), with different anions; i.e., [Zn(μ-bpdh)(H₂O)₄](ClO₄)₂·2bpdh (1) and [Zn(μ-bpdh)(H₂O)₄](NO₃)₂·2bpdh (2), were synthesized and characterized by IR spectroscopy, elemental analyses and X-ray crystallography. Compounds 1 and 2 are 1D coordination polymers and the zinc atoms are linked by four oxygen atoms from water molecules and two nitrogen atoms of bpdh ligands. There are two uncoordinated bpdh ligands that, along with the perchlorate or nitrate anions, form hydrogen bonds with water molecules. ZnO nanoparticles were obtained by thermolysis of 1–2 in oleic acid at 280 °C in air. The ZnO nanoparticles were characterized by X-ray diffraction and scanning electron microscopy.     

Seven Coordinated Metal Complexes derived from (3-Carboxymethoxy-Naphthalen-2-yloxy)-Acetic Acid and Coordination Polymers

A design principle for seven coordinated metal carboxylate complexes and coordination polymers of Mn(II), Cd(II) and Na(I) derived from (3-carboxymethoxy-naphthalen-2-yloxy)-acetic acid (LH2) is presented. The complexes/coordination polymer [Mn(L)(H₂O)₃]·3H₂O (1), [{Cd(L)(H₂O)₂}·H₂O]_n (2); [Cd(L)(py)₃]·3H₂O (3) have metal ions in pentagonal bipyramid environments (py = pyridine). The coordination polymer [{Cd(L)(H₂O)₂}·H₂O]_n (2) may be considered to be the self-assembly of hexacoordinated [Cd(L)(H₂O)₂] units; it reacts with pyridine to form mono-nuclear complex 3. Depending on the reaction conditions, Ni-coordination polymers of L adopt different compositions. From the reaction carried out with NiCl₂ and NaOH in quinoline and water, a hetero bimetallic coordination polymer; namely, [[NaL(H₂O)]₂Ni(H₂O)₄]_n (4) is obtained. A similar reaction in pyridine-water solvent led to [{Ni(L)(py)₃}.py]_n (5). The coordination polymer 5 has pyridine in its interstices held by C–H···π interactions.     

Complexes of poly(2-<Emphasis Type="Italic">N,N</Emphasis>-dimethylaminoethyl) methacrylate with heavy metals II. Oxidation of cyclohexene with <Emphasis Type="Italic">tert</Emphasis>-butylhydroperoxide

Metal complexes of poly(2-N,N-dimethylaminoethyl) methacrylate were prepared by complex-forming with aqueous solutions of salts of FeSO₄.2H₂O; CoCl₂.6H₂O; CuCl₂.2H₂O; VOSO₄.5H₂O; Na₂MoO₄.2H₂O and Na₂WO₄.2H₂O. The catalytic activity of the complexes was studied in the oxidation of cyclohexene as a model reaction. The activities of the complexes synthesized towards the reaction of cyclohexene epoxidation can be arranged by the following order: PDMAEM-MoO₂ ²⁺> PDMAEM-VO²⁺ > PDMAEM-WO₂ ²⁺> PDMAEM-Co²⁺ > PDMAEM-Fe³⁺> PDMAEM-Cu²⁺. The complexes catalyzing the homolytic decomposition of tert-butylhydroperoxide increased the maximum yield of 2-cyclohexene-1-ol and 2-cyclohexene-1-on. The yield of cyclohexene oxide and 2-cyclohexene-1-ol were 58% and 13%, respectively.     

Hydrothermal Preparation, Crystal Structures, Spectroscopic and Thermal Analyses of Cadmium(II) and Cobalt(II) Coordination Polymers With Pyridine-2,3-dicarboxylic Acid

Two novel 1D coordination polymers, [M(μ-2,3-pydc)(H₂O)₃]_n (M = Cd for 1 and Co for 2) (2,3-pydcH₂ = pyridine-2,3-dicarboxylic acid) have been hydrothermally synthesized. Both complexes were characterized by elemental analysis and by IR and UV–Vis spectroscopy. Their molecular and crystal structures were determined by X-ray crystal structure analysis and their thermal stability by TGA-DTA methods. Compound 1 crystallizes in the orthorhombic Pca2 space group, while compound 2 crystallizes in the triclinic P−1 space group. Polymeric chains of 1 and 2 are composed of M(II) ions bridged by pyridine-2,3-dicarboxylate ions (2,3-pydc) in N,O,O′ fashion. Distorted octahedral coordination geometry around the metal ions is completed by three water molecules. A wide range of hydrogen bonding (of the O–H···O type) is also present in the crystal structures. These interactions lead to formation of a 3D structure for 1 and 2D network for 2.