Surface Dependence of CO₂ Adsorption on Zn₂GeO₄

An understanding of the interaction between Zn₂GeO₄ and the CO₂ molecule is vital for developing its role in the photocatalytic reduction of CO₂. In this study, we present the structure and energetics of CO₂ adsorbed onto the stoichiometric perfectly and the oxygen vacancy defect of Zn₂GeO₄ (010) and (001) surfaces using density functional theory slab calculations. The major finding is that the surface structure of the Zn₂GeO₄ is important for CO₂ adsorption and activation, i.e., the interaction of CO₂ with Zn₂GeO₄ surfaces is structure-dependent. The ability of CO₂ adsorption on (001) is higher than that of CO₂ adsorption on (010). For the (010) surface, the active sites O_2c···Ge_3c and Ge_3c–O_3c interact with the CO₂ molecule leading to a bidentate carbonate species. The presence of Ge_3c–O_2c···Ge_3c bonds on the (001) surface strengthens the interaction of CO₂ with the (001) surface, and results in a bridged carbonate-like species. Furthermore, a comparison of the calculated adsorption energies of CO₂ adsorption on perfect and defective Zn₂GeO₄ (010) and (001) surfaces shows that CO₂ has the strongest adsorption near a surface oxygen vacancy site, with an adsorption energy −1.05 to −2.17 eV, stronger than adsorption of CO₂ on perfect Zn₂GeO₄ surfaces (<i>E</i>_ads = −0.91 to −1.12 eV) or adsorption of CO₂ on a surface oxygen defect site (<i>E</i>_ads = −0.24 to −0.95 eV). Additionally, for the defective Zn₂GeO₄ surfaces, the oxygen vacancies are the active sites. CO₂ that adsorbs directly at the Vo site can be dissociated into CO and O and the Vo defect can be healed by the oxygen atom released during the dissociation process. On further analysis of the dissociative adsorption mechanism of CO₂ on the surface oxygen defect site, we concluded that dissociative adsorption of CO₂ favors the stepwise dissociation mechanism and the dissociation process can be described as CO₂ + Vo → CO₂^δ−/Vo → CO_adsorbed + O_surface. This result has an important implication for understanding the photoreduction of CO₂ by using Zn₂GeO₄ nanoribbons

Ancillary Ligands Dependent Structural Diversity of A Series of Metal–Organic Frameworks Based on 3,5-Bis(3-carboxyphenyl)pyridine

A series of novel multidimensional transition metal–organic frameworks (MOFs), [Cu­(Hbcpb)₂]_<i>n</i> (<b>1</b>), [Co­(bcpb)]_<i>n</i> (<b>2</b>), [Co­(Hbcpb)₂(1,4-bib)]<i>n</i> (<b>3</b>), {[M­(bcpb)­(1,4-bimb)]·xH₂O}<i>n</i> (<i>M</i> = Co (<b>4</b>), Cu (<b>5</b>), Ni (<b>6</b>), <i>x</i> = 1 for <b>5</b>, 2 for <b>4</b> and <b>6</b>), [Co­(bcpb)­(4,4′-bibp)]_<i>n</i> (7), {[Co­(bcpb)­(4,4′-bibp)]·2H₂O}_<i>n</i> (<b>8</b>), and [Ni₂(bcpb)₂(4,4′-bimbp)₂]_<i>n</i> (<b>9</b>), were synthesized under hydrothermal conditions in the presence of N-donor ancillary ligands [H₂bcpb = 3,5-bis­(3-carboxyphenyl)­pyridine, 1,4-bib = 1,4-bis­(1H-imidazol-4-yl)­benzene, 1,4-bimb = 1,4-bis­(imidazol-1-ylmethyl)­benzene, 4,4′-bibp = 4,4′-bis­(imidazol-1-yl)­biphenyl, 4,4′-bimbp = 4,4′-bis­(imidazol-1-ylmethyl)­biphenyl]. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. By adjusting the reaction pH, the H₂bcpb ligand is partially deprotonated to give the Hbcpb^– form in <b>1</b> and <b>3</b>, and completely deprotonated to afford the bcpb^2– form in <b>2</b> and <b>4</b>–<b>9</b>. Complex <b>1</b> exhibits a two-dimensional (2D) (3,6)-connected kgd topology with the Schläfli symbol of (4³)₂(4⁶·6⁶·8³). The three-dimensional (3D) framework of <b>2</b> is defined as a (4,4)-connected pts topology with the Schläfli symbol of (4²·8⁴). Complex <b>3</b> displays a (4,6)-connected pcu topology with the Schläfli symbol of (4¹²·6³) built from 4⁴ 2D nets with the help of 1,4-bib. Complexes <b>4</b>–<b>6</b> are isomorphism and show a 3D (3,5)-connected mbm framework with the Point Schläfli symbol of (4·6²)­(4·6⁶·8³). The supramolecular isomers of <b>7</b> and <b>8</b>, resulted from the different pH in the reaction, exhibit (3,5)-connected (4²·6⁷·8)­(4²·6) 3,5-L2 and (4,6)-connected (4⁴·6¹⁰·8)­(4⁴·6²) fsc topology, respectively. Complex <b>9</b> can be regard as an unprecedented (3,5)-connected 3D 3,5-T1 frameworks with the point Schläfli symbol of (4²·6⁵·8³)­(4²·6). The results revealed that the crystal architectures and the coordination modes of H₂bcpb are attributed to the factors, including metal cations, pH, and the N-donor ancillary ligands

Ancillary Ligands Dependent Structural Diversity of A Series of Metal–Organic Frameworks Based on 3,5-Bis(3-carboxyphenyl)pyridine

A series of novel multidimensional transition metal–organic frameworks (MOFs), [Cu­(Hbcpb)₂]_<i>n</i> (<b>1</b>), [Co­(bcpb)]_<i>n</i> (<b>2</b>), [Co­(Hbcpb)₂(1,4-bib)]<i>n</i> (<b>3</b>), {[M­(bcpb)­(1,4-bimb)]·xH₂O}<i>n</i> (<i>M</i> = Co (<b>4</b>), Cu (<b>5</b>), Ni (<b>6</b>), <i>x</i> = 1 for <b>5</b>, 2 for <b>4</b> and <b>6</b>), [Co­(bcpb)­(4,4′-bibp)]_<i>n</i> (7), {[Co­(bcpb)­(4,4′-bibp)]·2H₂O}_<i>n</i> (<b>8</b>), and [Ni₂(bcpb)₂(4,4′-bimbp)₂]_<i>n</i> (<b>9</b>), were synthesized under hydrothermal conditions in the presence of N-donor ancillary ligands [H₂bcpb = 3,5-bis­(3-carboxyphenyl)­pyridine, 1,4-bib = 1,4-bis­(1H-imidazol-4-yl)­benzene, 1,4-bimb = 1,4-bis­(imidazol-1-ylmethyl)­benzene, 4,4′-bibp = 4,4′-bis­(imidazol-1-yl)­biphenyl, 4,4′-bimbp = 4,4′-bis­(imidazol-1-ylmethyl)­biphenyl]. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. By adjusting the reaction pH, the H₂bcpb ligand is partially deprotonated to give the Hbcpb^– form in <b>1</b> and <b>3</b>, and completely deprotonated to afford the bcpb^2– form in <b>2</b> and <b>4</b>–<b>9</b>. Complex <b>1</b> exhibits a two-dimensional (2D) (3,6)-connected kgd topology with the Schläfli symbol of (4³)₂(4⁶·6⁶·8³). The three-dimensional (3D) framework of <b>2</b> is defined as a (4,4)-connected pts topology with the Schläfli symbol of (4²·8⁴). Complex <b>3</b> displays a (4,6)-connected pcu topology with the Schläfli symbol of (4¹²·6³) built from 4⁴ 2D nets with the help of 1,4-bib. Complexes <b>4</b>–<b>6</b> are isomorphism and show a 3D (3,5)-connected mbm framework with the Point Schläfli symbol of (4·6²)­(4·6⁶·8³). The supramolecular isomers of <b>7</b> and <b>8</b>, resulted from the different pH in the reaction, exhibit (3,5)-connected (4²·6⁷·8)­(4²·6) 3,5-L2 and (4,6)-connected (4⁴·6¹⁰·8)­(4⁴·6²) fsc topology, respectively. Complex <b>9</b> can be regard as an unprecedented (3,5)-connected 3D 3,5-T1 frameworks with the point Schläfli symbol of (4²·6⁵·8³)­(4²·6). The results revealed that the crystal architectures and the coordination modes of H₂bcpb are attributed to the factors, including metal cations, pH, and the N-donor ancillary ligands

Ancillary Ligands Dependent Structural Diversity of A Series of Metal–Organic Frameworks Based on 3,5-Bis(3-carboxyphenyl)pyridine

A series of novel multidimensional transition metal–organic frameworks (MOFs), [Cu­(Hbcpb)₂]_<i>n</i> (<b>1</b>), [Co­(bcpb)]_<i>n</i> (<b>2</b>), [Co­(Hbcpb)₂(1,4-bib)]<i>n</i> (<b>3</b>), {[M­(bcpb)­(1,4-bimb)]·xH₂O}<i>n</i> (<i>M</i> = Co (<b>4</b>), Cu (<b>5</b>), Ni (<b>6</b>), <i>x</i> = 1 for <b>5</b>, 2 for <b>4</b> and <b>6</b>), [Co­(bcpb)­(4,4′-bibp)]_<i>n</i> (7), {[Co­(bcpb)­(4,4′-bibp)]·2H₂O}_<i>n</i> (<b>8</b>), and [Ni₂(bcpb)₂(4,4′-bimbp)₂]_<i>n</i> (<b>9</b>), were synthesized under hydrothermal conditions in the presence of N-donor ancillary ligands [H₂bcpb = 3,5-bis­(3-carboxyphenyl)­pyridine, 1,4-bib = 1,4-bis­(1H-imidazol-4-yl)­benzene, 1,4-bimb = 1,4-bis­(imidazol-1-ylmethyl)­benzene, 4,4′-bibp = 4,4′-bis­(imidazol-1-yl)­biphenyl, 4,4′-bimbp = 4,4′-bis­(imidazol-1-ylmethyl)­biphenyl]. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. By adjusting the reaction pH, the H₂bcpb ligand is partially deprotonated to give the Hbcpb^– form in <b>1</b> and <b>3</b>, and completely deprotonated to afford the bcpb^2– form in <b>2</b> and <b>4</b>–<b>9</b>. Complex <b>1</b> exhibits a two-dimensional (2D) (3,6)-connected kgd topology with the Schläfli symbol of (4³)₂(4⁶·6⁶·8³). The three-dimensional (3D) framework of <b>2</b> is defined as a (4,4)-connected pts topology with the Schläfli symbol of (4²·8⁴). Complex <b>3</b> displays a (4,6)-connected pcu topology with the Schläfli symbol of (4¹²·6³) built from 4⁴ 2D nets with the help of 1,4-bib. Complexes <b>4</b>–<b>6</b> are isomorphism and show a 3D (3,5)-connected mbm framework with the Point Schläfli symbol of (4·6²)­(4·6⁶·8³). The supramolecular isomers of <b>7</b> and <b>8</b>, resulted from the different pH in the reaction, exhibit (3,5)-connected (4²·6⁷·8)­(4²·6) 3,5-L2 and (4,6)-connected (4⁴·6¹⁰·8)­(4⁴·6²) fsc topology, respectively. Complex <b>9</b> can be regard as an unprecedented (3,5)-connected 3D 3,5-T1 frameworks with the point Schläfli symbol of (4²·6⁵·8³)­(4²·6). The results revealed that the crystal architectures and the coordination modes of H₂bcpb are attributed to the factors, including metal cations, pH, and the N-donor ancillary ligands

Ancillary Ligands Dependent Structural Diversity of A Series of Metal–Organic Frameworks Based on 3,5-Bis(3-carboxyphenyl)pyridine

A series of novel multidimensional transition metal–organic frameworks (MOFs), [Cu­(Hbcpb)₂]_<i>n</i> (<b>1</b>), [Co­(bcpb)]_<i>n</i> (<b>2</b>), [Co­(Hbcpb)₂(1,4-bib)]<i>n</i> (<b>3</b>), {[M­(bcpb)­(1,4-bimb)]·xH₂O}<i>n</i> (<i>M</i> = Co (<b>4</b>), Cu (<b>5</b>), Ni (<b>6</b>), <i>x</i> = 1 for <b>5</b>, 2 for <b>4</b> and <b>6</b>), [Co­(bcpb)­(4,4′-bibp)]_<i>n</i> (7), {[Co­(bcpb)­(4,4′-bibp)]·2H₂O}_<i>n</i> (<b>8</b>), and [Ni₂(bcpb)₂(4,4′-bimbp)₂]_<i>n</i> (<b>9</b>), were synthesized under hydrothermal conditions in the presence of N-donor ancillary ligands [H₂bcpb = 3,5-bis­(3-carboxyphenyl)­pyridine, 1,4-bib = 1,4-bis­(1H-imidazol-4-yl)­benzene, 1,4-bimb = 1,4-bis­(imidazol-1-ylmethyl)­benzene, 4,4′-bibp = 4,4′-bis­(imidazol-1-yl)­biphenyl, 4,4′-bimbp = 4,4′-bis­(imidazol-1-ylmethyl)­biphenyl]. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. By adjusting the reaction pH, the H₂bcpb ligand is partially deprotonated to give the Hbcpb^– form in <b>1</b> and <b>3</b>, and completely deprotonated to afford the bcpb^2– form in <b>2</b> and <b>4</b>–<b>9</b>. Complex <b>1</b> exhibits a two-dimensional (2D) (3,6)-connected kgd topology with the Schläfli symbol of (4³)₂(4⁶·6⁶·8³). The three-dimensional (3D) framework of <b>2</b> is defined as a (4,4)-connected pts topology with the Schläfli symbol of (4²·8⁴). Complex <b>3</b> displays a (4,6)-connected pcu topology with the Schläfli symbol of (4¹²·6³) built from 4⁴ 2D nets with the help of 1,4-bib. Complexes <b>4</b>–<b>6</b> are isomorphism and show a 3D (3,5)-connected mbm framework with the Point Schläfli symbol of (4·6²)­(4·6⁶·8³). The supramolecular isomers of <b>7</b> and <b>8</b>, resulted from the different pH in the reaction, exhibit (3,5)-connected (4²·6⁷·8)­(4²·6) 3,5-L2 and (4,6)-connected (4⁴·6¹⁰·8)­(4⁴·6²) fsc topology, respectively. Complex <b>9</b> can be regard as an unprecedented (3,5)-connected 3D 3,5-T1 frameworks with the point Schläfli symbol of (4²·6⁵·8³)­(4²·6). The results revealed that the crystal architectures and the coordination modes of H₂bcpb are attributed to the factors, including metal cations, pH, and the N-donor ancillary ligands

Ancillary Ligands Dependent Structural Diversity of A Series of Metal–Organic Frameworks Based on 3,5-Bis(3-carboxyphenyl)pyridine

A series of novel multidimensional transition metal–organic frameworks (MOFs), [Cu­(Hbcpb)₂]_<i>n</i> (<b>1</b>), [Co­(bcpb)]_<i>n</i> (<b>2</b>), [Co­(Hbcpb)₂(1,4-bib)]<i>n</i> (<b>3</b>), {[M­(bcpb)­(1,4-bimb)]·xH₂O}<i>n</i> (<i>M</i> = Co (<b>4</b>), Cu (<b>5</b>), Ni (<b>6</b>), <i>x</i> = 1 for <b>5</b>, 2 for <b>4</b> and <b>6</b>), [Co­(bcpb)­(4,4′-bibp)]_<i>n</i> (7), {[Co­(bcpb)­(4,4′-bibp)]·2H₂O}_<i>n</i> (<b>8</b>), and [Ni₂(bcpb)₂(4,4′-bimbp)₂]_<i>n</i> (<b>9</b>), were synthesized under hydrothermal conditions in the presence of N-donor ancillary ligands [H₂bcpb = 3,5-bis­(3-carboxyphenyl)­pyridine, 1,4-bib = 1,4-bis­(1H-imidazol-4-yl)­benzene, 1,4-bimb = 1,4-bis­(imidazol-1-ylmethyl)­benzene, 4,4′-bibp = 4,4′-bis­(imidazol-1-yl)­biphenyl, 4,4′-bimbp = 4,4′-bis­(imidazol-1-ylmethyl)­biphenyl]. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. By adjusting the reaction pH, the H₂bcpb ligand is partially deprotonated to give the Hbcpb^– form in <b>1</b> and <b>3</b>, and completely deprotonated to afford the bcpb^2– form in <b>2</b> and <b>4</b>–<b>9</b>. Complex <b>1</b> exhibits a two-dimensional (2D) (3,6)-connected kgd topology with the Schläfli symbol of (4³)₂(4⁶·6⁶·8³). The three-dimensional (3D) framework of <b>2</b> is defined as a (4,4)-connected pts topology with the Schläfli symbol of (4²·8⁴). Complex <b>3</b> displays a (4,6)-connected pcu topology with the Schläfli symbol of (4¹²·6³) built from 4⁴ 2D nets with the help of 1,4-bib. Complexes <b>4</b>–<b>6</b> are isomorphism and show a 3D (3,5)-connected mbm framework with the Point Schläfli symbol of (4·6²)­(4·6⁶·8³). The supramolecular isomers of <b>7</b> and <b>8</b>, resulted from the different pH in the reaction, exhibit (3,5)-connected (4²·6⁷·8)­(4²·6) 3,5-L2 and (4,6)-connected (4⁴·6¹⁰·8)­(4⁴·6²) fsc topology, respectively. Complex <b>9</b> can be regard as an unprecedented (3,5)-connected 3D 3,5-T1 frameworks with the point Schläfli symbol of (4²·6⁵·8³)­(4²·6). The results revealed that the crystal architectures and the coordination modes of H₂bcpb are attributed to the factors, including metal cations, pH, and the N-donor ancillary ligands

Hollow Anatase TiO₂ Octahedrons with Exposed High-Index {102} Facets for Improved Dye-Sensitized Photoredox Catalysis Activity

The high activity of exposed facets and large surface area have significant effects on the performance of photocatalysts because most of the photoreactivity properties of materials are related to surface processes. The strategy of combining high-index facets and a hollow structure into one material will provide a new way for designing effective photocatalysts, possessing active exposed facets and a large surface area at the same time. However, fabricating one material with both high-index facets and a hollow structure is still a great challenge due to their thermodynamic instability. Here, hollow anatase TiO₂ octahedrons exposed with high-index (102) facets (HTO-102) were successfully fabricated for the first time by a facile hydrothermal method using HF and H₂O₂ as morphology controlling agents. Compared with two other catalysts (a solid sharp octahedron with (101) facets (SSO-101) and a hollow sharp octahedron with (101) facets (HSO-101)), HTO-102 particles exhibit a better photochemical activity for the selective aerobic oxidation of organic sulfides under visible-light irradiation. Experimental results and theoretical calculations indicate that the excellent photocatalytic activity of HTO-102 particles is mainly due to the synergistic effects of its hollow structure and exposed high-index (102) facets

Ancillary Ligands Dependent Structural Diversity of A Series of Metal–Organic Frameworks Based on 3,5-Bis(3-carboxyphenyl)pyridine

A series of novel multidimensional transition metal–organic frameworks (MOFs), [Cu­(Hbcpb)₂]_<i>n</i> (<b>1</b>), [Co­(bcpb)]_<i>n</i> (<b>2</b>), [Co­(Hbcpb)₂(1,4-bib)]<i>n</i> (<b>3</b>), {[M­(bcpb)­(1,4-bimb)]·xH₂O}<i>n</i> (<i>M</i> = Co (<b>4</b>), Cu (<b>5</b>), Ni (<b>6</b>), <i>x</i> = 1 for <b>5</b>, 2 for <b>4</b> and <b>6</b>), [Co­(bcpb)­(4,4′-bibp)]_<i>n</i> (7), {[Co­(bcpb)­(4,4′-bibp)]·2H₂O}_<i>n</i> (<b>8</b>), and [Ni₂(bcpb)₂(4,4′-bimbp)₂]_<i>n</i> (<b>9</b>), were synthesized under hydrothermal conditions in the presence of N-donor ancillary ligands [H₂bcpb = 3,5-bis­(3-carboxyphenyl)­pyridine, 1,4-bib = 1,4-bis­(1H-imidazol-4-yl)­benzene, 1,4-bimb = 1,4-bis­(imidazol-1-ylmethyl)­benzene, 4,4′-bibp = 4,4′-bis­(imidazol-1-yl)­biphenyl, 4,4′-bimbp = 4,4′-bis­(imidazol-1-ylmethyl)­biphenyl]. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. By adjusting the reaction pH, the H₂bcpb ligand is partially deprotonated to give the Hbcpb^– form in <b>1</b> and <b>3</b>, and completely deprotonated to afford the bcpb^2– form in <b>2</b> and <b>4</b>–<b>9</b>. Complex <b>1</b> exhibits a two-dimensional (2D) (3,6)-connected kgd topology with the Schläfli symbol of (4³)₂(4⁶·6⁶·8³). The three-dimensional (3D) framework of <b>2</b> is defined as a (4,4)-connected pts topology with the Schläfli symbol of (4²·8⁴). Complex <b>3</b> displays a (4,6)-connected pcu topology with the Schläfli symbol of (4¹²·6³) built from 4⁴ 2D nets with the help of 1,4-bib. Complexes <b>4</b>–<b>6</b> are isomorphism and show a 3D (3,5)-connected mbm framework with the Point Schläfli symbol of (4·6²)­(4·6⁶·8³). The supramolecular isomers of <b>7</b> and <b>8</b>, resulted from the different pH in the reaction, exhibit (3,5)-connected (4²·6⁷·8)­(4²·6) 3,5-L2 and (4,6)-connected (4⁴·6¹⁰·8)­(4⁴·6²) fsc topology, respectively. Complex <b>9</b> can be regard as an unprecedented (3,5)-connected 3D 3,5-T1 frameworks with the point Schläfli symbol of (4²·6⁵·8³)­(4²·6). The results revealed that the crystal architectures and the coordination modes of H₂bcpb are attributed to the factors, including metal cations, pH, and the N-donor ancillary ligands

Ancillary Ligands Dependent Structural Diversity of A Series of Metal–Organic Frameworks Based on 3,5-Bis(3-carboxyphenyl)pyridine

A series of novel multidimensional transition metal–organic frameworks (MOFs), [Cu­(Hbcpb)₂]_<i>n</i> (<b>1</b>), [Co­(bcpb)]_<i>n</i> (<b>2</b>), [Co­(Hbcpb)₂(1,4-bib)]<i>n</i> (<b>3</b>), {[M­(bcpb)­(1,4-bimb)]·xH₂O}<i>n</i> (<i>M</i> = Co (<b>4</b>), Cu (<b>5</b>), Ni (<b>6</b>), <i>x</i> = 1 for <b>5</b>, 2 for <b>4</b> and <b>6</b>), [Co­(bcpb)­(4,4′-bibp)]_<i>n</i> (7), {[Co­(bcpb)­(4,4′-bibp)]·2H₂O}_<i>n</i> (<b>8</b>), and [Ni₂(bcpb)₂(4,4′-bimbp)₂]_<i>n</i> (<b>9</b>), were synthesized under hydrothermal conditions in the presence of N-donor ancillary ligands [H₂bcpb = 3,5-bis­(3-carboxyphenyl)­pyridine, 1,4-bib = 1,4-bis­(1H-imidazol-4-yl)­benzene, 1,4-bimb = 1,4-bis­(imidazol-1-ylmethyl)­benzene, 4,4′-bibp = 4,4′-bis­(imidazol-1-yl)­biphenyl, 4,4′-bimbp = 4,4′-bis­(imidazol-1-ylmethyl)­biphenyl]. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. By adjusting the reaction pH, the H₂bcpb ligand is partially deprotonated to give the Hbcpb^– form in <b>1</b> and <b>3</b>, and completely deprotonated to afford the bcpb^2– form in <b>2</b> and <b>4</b>–<b>9</b>. Complex <b>1</b> exhibits a two-dimensional (2D) (3,6)-connected kgd topology with the Schläfli symbol of (4³)₂(4⁶·6⁶·8³). The three-dimensional (3D) framework of <b>2</b> is defined as a (4,4)-connected pts topology with the Schläfli symbol of (4²·8⁴). Complex <b>3</b> displays a (4,6)-connected pcu topology with the Schläfli symbol of (4¹²·6³) built from 4⁴ 2D nets with the help of 1,4-bib. Complexes <b>4</b>–<b>6</b> are isomorphism and show a 3D (3,5)-connected mbm framework with the Point Schläfli symbol of (4·6²)­(4·6⁶·8³). The supramolecular isomers of <b>7</b> and <b>8</b>, resulted from the different pH in the reaction, exhibit (3,5)-connected (4²·6⁷·8)­(4²·6) 3,5-L2 and (4,6)-connected (4⁴·6¹⁰·8)­(4⁴·6²) fsc topology, respectively. Complex <b>9</b> can be regard as an unprecedented (3,5)-connected 3D 3,5-T1 frameworks with the point Schläfli symbol of (4²·6⁵·8³)­(4²·6). The results revealed that the crystal architectures and the coordination modes of H₂bcpb are attributed to the factors, including metal cations, pH, and the N-donor ancillary ligands

Ancillary Ligands Dependent Structural Diversity of A Series of Metal–Organic Frameworks Based on 3,5-Bis(3-carboxyphenyl)pyridine

A series of novel multidimensional transition metal–organic frameworks (MOFs), [Cu­(Hbcpb)₂]_<i>n</i> (<b>1</b>), [Co­(bcpb)]_<i>n</i> (<b>2</b>), [Co­(Hbcpb)₂(1,4-bib)]<i>n</i> (<b>3</b>), {[M­(bcpb)­(1,4-bimb)]·xH₂O}<i>n</i> (<i>M</i> = Co (<b>4</b>), Cu (<b>5</b>), Ni (<b>6</b>), <i>x</i> = 1 for <b>5</b>, 2 for <b>4</b> and <b>6</b>), [Co­(bcpb)­(4,4′-bibp)]_<i>n</i> (7), {[Co­(bcpb)­(4,4′-bibp)]·2H₂O}_<i>n</i> (<b>8</b>), and [Ni₂(bcpb)₂(4,4′-bimbp)₂]_<i>n</i> (<b>9</b>), were synthesized under hydrothermal conditions in the presence of N-donor ancillary ligands [H₂bcpb = 3,5-bis­(3-carboxyphenyl)­pyridine, 1,4-bib = 1,4-bis­(1H-imidazol-4-yl)­benzene, 1,4-bimb = 1,4-bis­(imidazol-1-ylmethyl)­benzene, 4,4′-bibp = 4,4′-bis­(imidazol-1-yl)­biphenyl, 4,4′-bimbp = 4,4′-bis­(imidazol-1-ylmethyl)­biphenyl]. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. By adjusting the reaction pH, the H₂bcpb ligand is partially deprotonated to give the Hbcpb^– form in <b>1</b> and <b>3</b>, and completely deprotonated to afford the bcpb^2– form in <b>2</b> and <b>4</b>–<b>9</b>. Complex <b>1</b> exhibits a two-dimensional (2D) (3,6)-connected kgd topology with the Schläfli symbol of (4³)₂(4⁶·6⁶·8³). The three-dimensional (3D) framework of <b>2</b> is defined as a (4,4)-connected pts topology with the Schläfli symbol of (4²·8⁴). Complex <b>3</b> displays a (4,6)-connected pcu topology with the Schläfli symbol of (4¹²·6³) built from 4⁴ 2D nets with the help of 1,4-bib. Complexes <b>4</b>–<b>6</b> are isomorphism and show a 3D (3,5)-connected mbm framework with the Point Schläfli symbol of (4·6²)­(4·6⁶·8³). The supramolecular isomers of <b>7</b> and <b>8</b>, resulted from the different pH in the reaction, exhibit (3,5)-connected (4²·6⁷·8)­(4²·6) 3,5-L2 and (4,6)-connected (4⁴·6¹⁰·8)­(4⁴·6²) fsc topology, respectively. Complex <b>9</b> can be regard as an unprecedented (3,5)-connected 3D 3,5-T1 frameworks with the point Schläfli symbol of (4²·6⁵·8³)­(4²·6). The results revealed that the crystal architectures and the coordination modes of H₂bcpb are attributed to the factors, including metal cations, pH, and the N-donor ancillary ligands