Ag^I/V^V Heterobimetallic Frameworks Generated from Novel-Type {Ag₂(VO₂F₂)₂(triazole)₄} Secondary Building Blocks: A New Aspect in the Design of SVOF Hybrids

A series of new silver­(I)-containing MOFs [Ag₂(<i>tr</i>_<i>2</i><i>ad</i>)₂]­(ClO₄)₂ (<b>1</b>), [Ag₂(VO₂F₂)₂(<i>tr</i>_<i>2</i><i>ad</i>)₂]·H₂O (<b>2</b>), [Ag₂(VO₂F₂)₂(<i>tr</i>_<i>2</i><i>eth</i>)₂(H₂O)₂] (<b>3</b>), and [Ag₂(VO₂F₂)₂(<i>tr</i>_<i>2</i><i>cy</i>)₂]·4H₂O (<b>4</b>) supported by 4-substituted bifunctional 1,2,4-triazole ligands (<i>tr</i>_<i>2</i><i>ad</i> = 1,3-bis­(1,2,4-triazol-4-yl)­adamantane, <i>tr</i>_<i>2</i><i>eth</i> = 1,2-bis­(1,2,4-triazol-4-yl)­ethane, <i>tr</i>_<i>2</i><i>cy</i> = <i>trans</i>-1,4-bis­(1,2,4-triazol-4-yl)­cyclohexane) were hydrothermally synthesized and structurally characterized. In these complexes, the triazole heterocycle as an N¹,N²-bridge links either two adjacent Ag–Ag or Ag–V centers at short distances forming polynuclear clusters. The crystal structure of compound <b>1</b> is based on cationic {Ag₂(<i>tr</i>)₄}²⁺ fragments connected in a 2D rhombohedral grid network with (4,4) topology. The neighboring layers are tightly packed into a 3D array by means of argentophilic interactions (Ag···Ag 3.28 Å). Bridging between different metal atoms through the triazole groups assists formation of heterobimetallic Ag^I/V^V secondary building blocks in a linear V–Ag–Ag–V sequence that is observed in complexes <b>2</b>–<b>4</b>. These unprecedented tetranuclear {Ag₂(VO₂F₂)₂(<i>tr</i>)₄} units (the intermetal Ag–Ag and Ag–V distances are 4.24–4.36 and 3.74–3.81 Å, respectively), in which vanadium­(V) oxofluoride units possess distorted trigonal bipyramidal environment {VO₂F₂N}¯, are incorporated into 1D ribbon (<b>2</b>) or 2D square nets (<b>3</b>, <b>4</b>) using bitopic μ₄-triazole ligands. The valence bond calculation for vanadium atoms shows +V oxidation state in the corresponding compounds. Thermal stability and photoluminescence properties were studied for all reported coordination polymers

Ag^I/V^V Heterobimetallic Frameworks Generated from Novel-Type {Ag₂(VO₂F₂)₂(triazole)₄} Secondary Building Blocks: A New Aspect in the Design of SVOF Hybrids

A series of new silver­(I)-containing MOFs [Ag₂(<i>tr</i>_<i>2</i><i>ad</i>)₂]­(ClO₄)₂ (<b>1</b>), [Ag₂(VO₂F₂)₂(<i>tr</i>_<i>2</i><i>ad</i>)₂]·H₂O (<b>2</b>), [Ag₂(VO₂F₂)₂(<i>tr</i>_<i>2</i><i>eth</i>)₂(H₂O)₂] (<b>3</b>), and [Ag₂(VO₂F₂)₂(<i>tr</i>_<i>2</i><i>cy</i>)₂]·4H₂O (<b>4</b>) supported by 4-substituted bifunctional 1,2,4-triazole ligands (<i>tr</i>_<i>2</i><i>ad</i> = 1,3-bis­(1,2,4-triazol-4-yl)­adamantane, <i>tr</i>_<i>2</i><i>eth</i> = 1,2-bis­(1,2,4-triazol-4-yl)­ethane, <i>tr</i>_<i>2</i><i>cy</i> = <i>trans</i>-1,4-bis­(1,2,4-triazol-4-yl)­cyclohexane) were hydrothermally synthesized and structurally characterized. In these complexes, the triazole heterocycle as an N¹,N²-bridge links either two adjacent Ag–Ag or Ag–V centers at short distances forming polynuclear clusters. The crystal structure of compound <b>1</b> is based on cationic {Ag₂(<i>tr</i>)₄}²⁺ fragments connected in a 2D rhombohedral grid network with (4,4) topology. The neighboring layers are tightly packed into a 3D array by means of argentophilic interactions (Ag···Ag 3.28 Å). Bridging between different metal atoms through the triazole groups assists formation of heterobimetallic Ag^I/V^V secondary building blocks in a linear V–Ag–Ag–V sequence that is observed in complexes <b>2</b>–<b>4</b>. These unprecedented tetranuclear {Ag₂(VO₂F₂)₂(<i>tr</i>)₄} units (the intermetal Ag–Ag and Ag–V distances are 4.24–4.36 and 3.74–3.81 Å, respectively), in which vanadium­(V) oxofluoride units possess distorted trigonal bipyramidal environment {VO₂F₂N}¯, are incorporated into 1D ribbon (<b>2</b>) or 2D square nets (<b>3</b>, <b>4</b>) using bitopic μ₄-triazole ligands. The valence bond calculation for vanadium atoms shows +V oxidation state in the corresponding compounds. Thermal stability and photoluminescence properties were studied for all reported coordination polymers