A new complex [Cd(hba)2(bib)]n·nH2O(1,Hhba = 3-hydroxybenzoic acid,bib = 1,4-bis(imidazol-1-yl)-butane) has been hydrothermally synthesized and characterized by elemental analysis,IR spectrum,thermogravim...A new complex [Cd(hba)2(bib)]n·nH2O(1,Hhba = 3-hydroxybenzoic acid,bib = 1,4-bis(imidazol-1-yl)-butane) has been hydrothermally synthesized and characterized by elemental analysis,IR spectrum,thermogravimetric analysis,fluorescence spectrum,and singlecrystal X-ray diffraction.Yellow crystal crystallizes in the orthorhombic system,space group Pbca with a = 16.220(5),b = 14.980(5),c = 20.521(5) ?,V = 4986(3) ?~3,C(24)H(26)CdN4O7,Mr = 594.89,Dc = 1.585 g/cm^3,μ(Mo Kα) = 0.927 mm^(-1),F(000) = 2416,Z = 8,the final R = 0.0242 and w R = 0.0589 for 4076 observed reflections(I 〉 2s(I)).In 1,the Cd(Ⅱ) ion takes a six-coordination mode,and bib ligand bridges adjacent Cd(Ⅱ) ions to generate 1D zigzag chains; these neighboring chains are connected by O–H···O hydrogen bonding interactions,producing a 2D folded layered structure.Furthermore,by O–H···O hydrogen bonding between layers and layers,a 3D supramolecular architecture is formed.In addition,we analyzed Natural Bond Orbital(NBO) in using the PBE0/LANL2 DZ method built in Gaussian 03 Program.The calculation results indicated obvious covalent interaction between the coordinated atoms and Cd(Ⅱ) ion.展开更多
A new coordination polymer {[Cd(C_(21)H_(14)N_6)(C_8H_4O_4)]·H_2O}_n(1) was synthesized by an elaborate design via the reaction of 3-(2,6-di(pyrazin-2-yl)pyridin-4-yl)-1H-indole(bppi),1,4-benzene-...A new coordination polymer {[Cd(C_(21)H_(14)N_6)(C_8H_4O_4)]·H_2O}_n(1) was synthesized by an elaborate design via the reaction of 3-(2,6-di(pyrazin-2-yl)pyridin-4-yl)-1H-indole(bppi),1,4-benzene-dicarboxylic acid(H2bdc) and cadmium(Ⅱ) nitrate in CH_3OH/H_2O mixed solvents. Complex 1 crystallizes in orthorhombic,space group Ccca with a = 20.012(4),b = 31.881(6),c = 19.808(4) ?,V = 12638(4) ?~3,Z = 16,C_(29)H_(20)CdN_6O_5,M_r = 644.91,D_c = 1.356 g·cm^(-3),μ = 0.735 mm^(-1),F(000) = 5184,GOOF = 1.046,the final R = 0.0405 and wR = 0.1063 for 6870 observed reflections(I 〉 2σ(I)). The Cd(Ⅱ) centre is hepta-coordinated by three N and four O atoms from one bppi terminal ligand and two bdc2– ligands,respectively,displaying a capped trigonal prism geometry. Structure extension gives coordination polymeric chains,in which the bdc2– linkers connect Cd(Ⅱ) cations into a one-dimensional(1D) coordination polymer along the c axis,giving zigzag chains with the Cd···Cd separation of 11.178(1) ?. The adjacent bppi terminal ligands in the chains are anti-periplanar conformation. The three-dimensional(3D) structure is stabilized by π···π stacking and hydrogen-bonding interactions to form a supramolecular self-penetrating network with 1D channels. In 1,there are voids 2999.7 ?~3 with 23.7% of per unit cell volume. Thermal analysis indicates that the framework of 1 is stable until 651 K and the photoluminescence of 1 in the solid shows very weak fluorescence at 382 and 560 nm upon excitation at 310 nm.展开更多
A new coordination polymer, namely [Zn(pdc)(bbi)]n {H2 pdc = 2,3-pyridine dicar- boxylic acid, bbi = 1,1-(1,4-butanediyl)bis(imidazole)}, has been prepared under hydrothermal conditions and characterized by el...A new coordination polymer, namely [Zn(pdc)(bbi)]n {H2 pdc = 2,3-pyridine dicar- boxylic acid, bbi = 1,1-(1,4-butanediyl)bis(imidazole)}, has been prepared under hydrothermal conditions and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21 /n with a = 8.436(3), b = 16.988(5), c = 12.106(4), β = 92.204(5)°, V = 1733.6(9)3, Z = 4, C17 H17 N5 O4 Zn, Mr = 420.73, Dc = 1.612 g/cm3, F(000) = 864, μ(MoKa) = 0.452 mm-1, the R = 0.0672 and wR = 0.1645. In the mononuclear complex, each Zn(II) is five-coordinated by one carboxylate O and one pyridyl N atoms from one pdc anion, one carboxylate O atom from another pdc anion, and two N atoms from two bib ligands. The Zn(II) ions are connected by pdc ligands to form skeleton chains, and bbi ligands further link them to construct a 2D framework. The thermal and luminescence properties of the complex were also investigated.展开更多
A new Co(Ⅱ) coordination polymer, [Co(1,4-chdc)(L)(H2O)]n(1), was synthesized under hydrothermal condition(1,4-H2chdc = 1,4-cyclohexanedicarboxylic acid, L = 2-(4-fluoro-phenyl)-1 H-imidazo[4,5-f][1,10]p...A new Co(Ⅱ) coordination polymer, [Co(1,4-chdc)(L)(H2O)]n(1), was synthesized under hydrothermal condition(1,4-H2chdc = 1,4-cyclohexanedicarboxylic acid, L = 2-(4-fluoro-phenyl)-1 H-imidazo[4,5-f][1,10]phenanthroline). Its crystal structure was determined by single-crystal X-ray diffraction. 1 crystallizes in triclinic, space group P1 with a = 8.790(5), b = 10.486(5), c = 13.305(5) ?, α = 87.391(5), β = 82.925(5), γ = 81.841(5)o, V = 1204.2(10) ?3, Z = 2, C27H23FN4O5Co, Mr = 561.42, Dc = 1.548 g/cm3, F(000) = 578, μ(Mo Ka) = 0.769 mm-1, R = 0.0415 and wR = 0.1043. In 1, each 1,4-chdc anion bridges two neighboring Co(Ⅱ) atoms to give a chain structure. The L ligands are attached on one side of the chain through chelating the Co(Ⅱ) atoms, and are stacked with those of an adjacent chain through π-π interactions, yielding a double-chain structure. The double-chain structures are linked into a supramolecular layer structure through N–H···O hydrogen-bonding interactions between the adjacent double-chain structures. Moreover, the thermal behavior of 1 was also studied.展开更多
A new coordination complex [Cd(pda)(pyz)(H2O)2]n(1, H2 pda = 1,4-phenylenediacetic acid, pyz = pyrazine) have been synthesized and structurally characterized. Crystal data for the title complex are as follows: orthorh...A new coordination complex [Cd(pda)(pyz)(H2O)2]n(1, H2 pda = 1,4-phenylenediacetic acid, pyz = pyrazine) have been synthesized and structurally characterized. Crystal data for the title complex are as follows: orthorhombic system, space group Ccmb with a = 11.5245(3) b = 19.5069(5) c = 11.4231(3) A, V = 2568.00(12) A3, Mr = 188.31, Z = 16, F(000) = 1480, Dc = 1.948 g/cm3, μ(Mo Kα) = 1.725 mm-1, R = 0.0195 and w R = 0.0462 for 1357 observed reflections with I 】 2σ(I). In the title complex, the central Cd(II) ion is located in a distorted octahedral coordination environment. Two Cd(II) ions are bridged by two pda2- ligands and one pyz ligand to form a bi-loop structure. Luminescent property of the complex has also been studied.展开更多
The title compound (C12H15NO13S, Mr = 413.31) was synthesized by the nitration of napthalene-1,4-dicarboxylate acid in mixed nitric and sulfuric acids. It crystallizes in monoclinic, space group P2 1/c with a = 8.10...The title compound (C12H15NO13S, Mr = 413.31) was synthesized by the nitration of napthalene-1,4-dicarboxylate acid in mixed nitric and sulfuric acids. It crystallizes in monoclinic, space group P2 1/c with a = 8.100(1), b = 24.369(3), c = 8.634(1) A, β = 105.380(2)°, V = 1643.1(4) A^3, Z = 4, Dc = 1.671 g/cm^3, F(000) = 856, μ(MoKa) = 0.273 mm^- 1, T = 294(2) K, the final R = 0.0400 and wR = 0.1021 for 2866 observed reflections with I 〉 2σ(I). In this crystal there exist a number of H-bonds which link the molecules to form a three-dimensional infinite network structure. The thermal decomposition of the title compound was investigated by using TG-DTG and DSC techniques.展开更多
One novel nickel coordination polymer, {[Ni(OTP)(bib)1.5(H2O)]·2H2O}n(1, H2 OTP = 2-hydroxy-5-(3',5'-terephthalic acid) pyridine, bib = 1,4-bis(1-imdazoly)benzene), has been synthesized and characte...One novel nickel coordination polymer, {[Ni(OTP)(bib)1.5(H2O)]·2H2O}n(1, H2 OTP = 2-hydroxy-5-(3',5'-terephthalic acid) pyridine, bib = 1,4-bis(1-imdazoly)benzene), has been synthesized and characterized by elemental analysis(EA), IR, powder X-ray diffraction(PXRD), and thermogravimetric(TG) analyses. The crystal of 1 crystallizes in monoclinic, space group P21/n with a = 12.2860(5), b = 13.8246(6), c = 19.0140(8) A, β = 104.3870(1)°, V = 3128.2(2) A3, Z = 4, C32H28N7 Ni O8, Mr = 697.32, Dc = 1.481 g/cm^3, F(000) = 1444 and μ(Mo Kα) = 0.684 mm-1. The final R = 0.0704 and w R = 0.1764 for 5485 observed reflections with I 2σ(I) and R = 0.1087 and wR = 0.2010 for all data. Topology analysis reveals that complex 1 is a 3D 2-fold interpenetrated {4^4·6^6}-nov net based on the 1D [Ni(OTP)]n chain and the 2D [Ni2(bib)3]n sql sheet. And the variable-temperature magnetic susceptibility measurements exhibit weak antiferromagnetic coupling interaction.展开更多
A new Pb(Ⅱ) coordination polymer, [Pb(1,4-chdc)(L)]_n·nH_2O(1), was synthesized under hydrothermal condition(1,4-H2 chdc = 1,4-cyclohexanedicarboxylic acid and L = 2-(3-fluorophenyl)-1H-imidazo[4,5-f]...A new Pb(Ⅱ) coordination polymer, [Pb(1,4-chdc)(L)]_n·nH_2O(1), was synthesized under hydrothermal condition(1,4-H2 chdc = 1,4-cyclohexanedicarboxylic acid and L = 2-(3-fluorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline). Its crystal structure was determined by singlecrystal X-ray diffraction. Compound 1 crystallizes in triclinic, space group P1 with a = 9.1182(8), b = 11.3249(10), c = 12.7326(12) A, α = 77.897(2), β = 81.644(2), γ = 84.491(2)°, V = 1269.0(2) A^3, Z = 2, C_(27)H_(24)FN_4O_5Pb, M_r = 710.69, D_c = 1.860 g/cm^3, F(000) = 690, μ(MoKa) = 6.701 mm^(-1), R = 0.0349 and wR = 0.0746. In 1, each 1,4-chdc anion bridges two neighboring Pb(Ⅱ) atoms in a bidentate chelating coordination mode to give a chain structure. The L ligands are attached on one side of the chain through chelating the Pb(Ⅱ) atoms, and are stacked with those of an adjacent chain through π-π interactions, yielding a layer structure. The O-H···O and N-H···O hydrogen bonding interactions further stabilize the supramolecular layer structure of 1. Moreover, solid state luminescent property of 1 was also studied.展开更多
A novel redox-active bipyridinium ligand N-(3-carboxyphenyl)-4,4'-bipyridinium chloride (HCPBPyC1) and its coordination polymer {[Cd2(CPBPy)2(BDC)(H2O)2Cl2]·6H2O}n 1 (H2BDC = benzene-1,4-dicarboxylic ...A novel redox-active bipyridinium ligand N-(3-carboxyphenyl)-4,4'-bipyridinium chloride (HCPBPyC1) and its coordination polymer {[Cd2(CPBPy)2(BDC)(H2O)2Cl2]·6H2O}n 1 (H2BDC = benzene-1,4-dicarboxylic acid) were synthesized and characterized. Crystallographic data for 1: C42H44Cd2Cl2N4O16, Mr = 1156.51, monoclinic, space group C2/c, a = 21.046(3), b = 11.0036(15), c = 20.012(3)A, β = 98.694(8)°, Z = 4, V = 4581.1(11)A3, Dc = 1.677 g/cm^3, F(000) = 2280 and μ = 1.120 mm^-1. Complex 1 possesses a thick and undulated two-dimensional layer with (6,3) topology, which interpenetrates with two others (above and below) to extend into a three-dimensional supramolecular framework.展开更多
基金supported by the Science and Technology Development Project of Jilin Provincial Science&Technology Department(201205080)the Science and Technology Research Projects of the Education Office of Jilin Province(No.2013.384)
文摘A new complex [Cd(hba)2(bib)]n·nH2O(1,Hhba = 3-hydroxybenzoic acid,bib = 1,4-bis(imidazol-1-yl)-butane) has been hydrothermally synthesized and characterized by elemental analysis,IR spectrum,thermogravimetric analysis,fluorescence spectrum,and singlecrystal X-ray diffraction.Yellow crystal crystallizes in the orthorhombic system,space group Pbca with a = 16.220(5),b = 14.980(5),c = 20.521(5) ?,V = 4986(3) ?~3,C(24)H(26)CdN4O7,Mr = 594.89,Dc = 1.585 g/cm^3,μ(Mo Kα) = 0.927 mm^(-1),F(000) = 2416,Z = 8,the final R = 0.0242 and w R = 0.0589 for 4076 observed reflections(I 〉 2s(I)).In 1,the Cd(Ⅱ) ion takes a six-coordination mode,and bib ligand bridges adjacent Cd(Ⅱ) ions to generate 1D zigzag chains; these neighboring chains are connected by O–H···O hydrogen bonding interactions,producing a 2D folded layered structure.Furthermore,by O–H···O hydrogen bonding between layers and layers,a 3D supramolecular architecture is formed.In addition,we analyzed Natural Bond Orbital(NBO) in using the PBE0/LANL2 DZ method built in Gaussian 03 Program.The calculation results indicated obvious covalent interaction between the coordinated atoms and Cd(Ⅱ) ion.
基金supported by the National Natural Science Foundation of China(Nos.21571118&21271121)
文摘A new coordination polymer {[Cd(C_(21)H_(14)N_6)(C_8H_4O_4)]·H_2O}_n(1) was synthesized by an elaborate design via the reaction of 3-(2,6-di(pyrazin-2-yl)pyridin-4-yl)-1H-indole(bppi),1,4-benzene-dicarboxylic acid(H2bdc) and cadmium(Ⅱ) nitrate in CH_3OH/H_2O mixed solvents. Complex 1 crystallizes in orthorhombic,space group Ccca with a = 20.012(4),b = 31.881(6),c = 19.808(4) ?,V = 12638(4) ?~3,Z = 16,C_(29)H_(20)CdN_6O_5,M_r = 644.91,D_c = 1.356 g·cm^(-3),μ = 0.735 mm^(-1),F(000) = 5184,GOOF = 1.046,the final R = 0.0405 and wR = 0.1063 for 6870 observed reflections(I 〉 2σ(I)). The Cd(Ⅱ) centre is hepta-coordinated by three N and four O atoms from one bppi terminal ligand and two bdc2– ligands,respectively,displaying a capped trigonal prism geometry. Structure extension gives coordination polymeric chains,in which the bdc2– linkers connect Cd(Ⅱ) cations into a one-dimensional(1D) coordination polymer along the c axis,giving zigzag chains with the Cd···Cd separation of 11.178(1) ?. The adjacent bppi terminal ligands in the chains are anti-periplanar conformation. The three-dimensional(3D) structure is stabilized by π···π stacking and hydrogen-bonding interactions to form a supramolecular self-penetrating network with 1D channels. In 1,there are voids 2999.7 ?~3 with 23.7% of per unit cell volume. Thermal analysis indicates that the framework of 1 is stable until 651 K and the photoluminescence of 1 in the solid shows very weak fluorescence at 382 and 560 nm upon excitation at 310 nm.
基金Supported by the Key Scientific and Technological Project of Henan(122102210250)the Foundation of Henan Educational Committee(13A150102)the key disciplines of analytical chemistry of Henan province
文摘A new coordination polymer, namely [Zn(pdc)(bbi)]n {H2 pdc = 2,3-pyridine dicar- boxylic acid, bbi = 1,1-(1,4-butanediyl)bis(imidazole)}, has been prepared under hydrothermal conditions and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21 /n with a = 8.436(3), b = 16.988(5), c = 12.106(4), β = 92.204(5)°, V = 1733.6(9)3, Z = 4, C17 H17 N5 O4 Zn, Mr = 420.73, Dc = 1.612 g/cm3, F(000) = 864, μ(MoKa) = 0.452 mm-1, the R = 0.0672 and wR = 0.1645. In the mononuclear complex, each Zn(II) is five-coordinated by one carboxylate O and one pyridyl N atoms from one pdc anion, one carboxylate O atom from another pdc anion, and two N atoms from two bib ligands. The Zn(II) ions are connected by pdc ligands to form skeleton chains, and bbi ligands further link them to construct a 2D framework. The thermal and luminescence properties of the complex were also investigated.
基金Supported by the National Natural Science Foundation of China(No.21607051)
文摘A new Co(Ⅱ) coordination polymer, [Co(1,4-chdc)(L)(H2O)]n(1), was synthesized under hydrothermal condition(1,4-H2chdc = 1,4-cyclohexanedicarboxylic acid, L = 2-(4-fluoro-phenyl)-1 H-imidazo[4,5-f][1,10]phenanthroline). Its crystal structure was determined by single-crystal X-ray diffraction. 1 crystallizes in triclinic, space group P1 with a = 8.790(5), b = 10.486(5), c = 13.305(5) ?, α = 87.391(5), β = 82.925(5), γ = 81.841(5)o, V = 1204.2(10) ?3, Z = 2, C27H23FN4O5Co, Mr = 561.42, Dc = 1.548 g/cm3, F(000) = 578, μ(Mo Ka) = 0.769 mm-1, R = 0.0415 and wR = 0.1043. In 1, each 1,4-chdc anion bridges two neighboring Co(Ⅱ) atoms to give a chain structure. The L ligands are attached on one side of the chain through chelating the Co(Ⅱ) atoms, and are stacked with those of an adjacent chain through π-π interactions, yielding a double-chain structure. The double-chain structures are linked into a supramolecular layer structure through N–H···O hydrogen-bonding interactions between the adjacent double-chain structures. Moreover, the thermal behavior of 1 was also studied.
基金Supported by the National Natural Science Foundation of China(No.21301069)the Natural Science Foundation of Shandong Province(No.ZR2012BQ004)
文摘A new coordination complex [Cd(pda)(pyz)(H2O)2]n(1, H2 pda = 1,4-phenylenediacetic acid, pyz = pyrazine) have been synthesized and structurally characterized. Crystal data for the title complex are as follows: orthorhombic system, space group Ccmb with a = 11.5245(3) b = 19.5069(5) c = 11.4231(3) A, V = 2568.00(12) A3, Mr = 188.31, Z = 16, F(000) = 1480, Dc = 1.948 g/cm3, μ(Mo Kα) = 1.725 mm-1, R = 0.0195 and w R = 0.0462 for 1357 observed reflections with I 】 2σ(I). In the title complex, the central Cd(II) ion is located in a distorted octahedral coordination environment. Two Cd(II) ions are bridged by two pda2- ligands and one pyz ligand to form a bi-loop structure. Luminescent property of the complex has also been studied.
基金This work was supported by the NNSFC (No. 20471008)
文摘The title compound (C12H15NO13S, Mr = 413.31) was synthesized by the nitration of napthalene-1,4-dicarboxylate acid in mixed nitric and sulfuric acids. It crystallizes in monoclinic, space group P2 1/c with a = 8.100(1), b = 24.369(3), c = 8.634(1) A, β = 105.380(2)°, V = 1643.1(4) A^3, Z = 4, Dc = 1.671 g/cm^3, F(000) = 856, μ(MoKa) = 0.273 mm^- 1, T = 294(2) K, the final R = 0.0400 and wR = 0.1021 for 2866 observed reflections with I 〉 2σ(I). In this crystal there exist a number of H-bonds which link the molecules to form a three-dimensional infinite network structure. The thermal decomposition of the title compound was investigated by using TG-DTG and DSC techniques.
基金supported by the Natural Science Foundation of Shandong Province(ZR2011BL020,ZR2012CM019)National Natural Science Foundation of China(21451001)Key Discipline and Innovation Team of Qilu Normal University
文摘One novel nickel coordination polymer, {[Ni(OTP)(bib)1.5(H2O)]·2H2O}n(1, H2 OTP = 2-hydroxy-5-(3',5'-terephthalic acid) pyridine, bib = 1,4-bis(1-imdazoly)benzene), has been synthesized and characterized by elemental analysis(EA), IR, powder X-ray diffraction(PXRD), and thermogravimetric(TG) analyses. The crystal of 1 crystallizes in monoclinic, space group P21/n with a = 12.2860(5), b = 13.8246(6), c = 19.0140(8) A, β = 104.3870(1)°, V = 3128.2(2) A3, Z = 4, C32H28N7 Ni O8, Mr = 697.32, Dc = 1.481 g/cm^3, F(000) = 1444 and μ(Mo Kα) = 0.684 mm-1. The final R = 0.0704 and w R = 0.1764 for 5485 observed reflections with I 2σ(I) and R = 0.1087 and wR = 0.2010 for all data. Topology analysis reveals that complex 1 is a 3D 2-fold interpenetrated {4^4·6^6}-nov net based on the 1D [Ni(OTP)]n chain and the 2D [Ni2(bib)3]n sql sheet. And the variable-temperature magnetic susceptibility measurements exhibit weak antiferromagnetic coupling interaction.
文摘A new Pb(Ⅱ) coordination polymer, [Pb(1,4-chdc)(L)]_n·nH_2O(1), was synthesized under hydrothermal condition(1,4-H2 chdc = 1,4-cyclohexanedicarboxylic acid and L = 2-(3-fluorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline). Its crystal structure was determined by singlecrystal X-ray diffraction. Compound 1 crystallizes in triclinic, space group P1 with a = 9.1182(8), b = 11.3249(10), c = 12.7326(12) A, α = 77.897(2), β = 81.644(2), γ = 84.491(2)°, V = 1269.0(2) A^3, Z = 2, C_(27)H_(24)FN_4O_5Pb, M_r = 710.69, D_c = 1.860 g/cm^3, F(000) = 690, μ(MoKa) = 6.701 mm^(-1), R = 0.0349 and wR = 0.0746. In 1, each 1,4-chdc anion bridges two neighboring Pb(Ⅱ) atoms in a bidentate chelating coordination mode to give a chain structure. The L ligands are attached on one side of the chain through chelating the Pb(Ⅱ) atoms, and are stacked with those of an adjacent chain through π-π interactions, yielding a layer structure. The O-H···O and N-H···O hydrogen bonding interactions further stabilize the supramolecular layer structure of 1. Moreover, solid state luminescent property of 1 was also studied.
基金the National Natural Science Foundation of China (No. 20671090/5037206)the Key Project from CAS (No. KJCX2. YW.H01)
文摘A novel redox-active bipyridinium ligand N-(3-carboxyphenyl)-4,4'-bipyridinium chloride (HCPBPyC1) and its coordination polymer {[Cd2(CPBPy)2(BDC)(H2O)2Cl2]·6H2O}n 1 (H2BDC = benzene-1,4-dicarboxylic acid) were synthesized and characterized. Crystallographic data for 1: C42H44Cd2Cl2N4O16, Mr = 1156.51, monoclinic, space group C2/c, a = 21.046(3), b = 11.0036(15), c = 20.012(3)A, β = 98.694(8)°, Z = 4, V = 4581.1(11)A3, Dc = 1.677 g/cm^3, F(000) = 2280 and μ = 1.120 mm^-1. Complex 1 possesses a thick and undulated two-dimensional layer with (6,3) topology, which interpenetrates with two others (above and below) to extend into a three-dimensional supramolecular framework.