Magnetic Nanosized {M^II₂₄}-Wheel-Based (M = Co, Ni) Coordination Polymers

Two 3D coordination polymers, [Co₂₄(OH)₁₂(SO₄)₁₂(ip)₆(DMSO)₁₈(H₂O)₆]·­(DMSO)₆­(EtOH)₆(H₂O)₃₆ (<b>1</b>·guests, ip = isophthalate) and [Ni₂₄(OH)₁₂(SO₄)₁₂(ip)₆(DMSO)₁₂(H₂O)₁₂]·­(DMSO)₆­(EtOH)₆(H₂O)₂₀ (<b>2</b>·guests), constructed with nanosized tetraicosanuclear Co^II and Ni^II wheels are solvothermally synthesized. Both complexes show intra- and interwheel dominant antiferromagnetic interactions

Magnetic Nanosized {M^II₂₄}-Wheel-Based (M = Co, Ni) Coordination Polymers

Two 3D coordination polymers, [Co₂₄(OH)₁₂(SO₄)₁₂(ip)₆(DMSO)₁₈(H₂O)₆]·­(DMSO)₆­(EtOH)₆(H₂O)₃₆ (<b>1</b>·guests, ip = isophthalate) and [Ni₂₄(OH)₁₂(SO₄)₁₂(ip)₆(DMSO)₁₂(H₂O)₁₂]·­(DMSO)₆­(EtOH)₆(H₂O)₂₀ (<b>2</b>·guests), constructed with nanosized tetraicosanuclear Co^II and Ni^II wheels are solvothermally synthesized. Both complexes show intra- and interwheel dominant antiferromagnetic interactions

Valence Tautomeric Transitions of Three One-Dimensional Cobalt Complexes

Three novel complexes, namely, [Co^III(3,5-DBCat)­(3,5-DBSq)­(bpe)]·2CH₃CN·2H₂O (<b>1</b>·<i>S</i>), [Co^III(3,5-DBCat)­(3,5-DBSq)­(azpy)]·2CH₃CN·2H₂O (<b>2</b>·<i>S</i>), and [Co^II(3,5-DBSq)₂(bpb)]­[Co^III(3,5-DBCat)­(3,5-DBSq)­(bpb)]_0.5·2CH₃CN·2H₂O (<b>3</b>·<i>S</i>), were synthesized and characterized by valence tautomeric (VT) X-ray diffraction and magnetic measurements [where 3,5-DBCatH₂ = 3,5-di-<i>tert</i>-butyl-catechol, 3,5-DBSqH = 3,5-di-<i>tert</i>-butyl-semiquinone, bpe = <i>trans</i>-bis­(4-pyridyl)­ethylene, azpy = <i>trans</i>-4,4′-azopyridine, and bpb = 1,4-bis­(4-pyridyl)­benzene]. The three complexes have similar one-dimensional chain structure building from bidentate-bridging pyridine ligands and planar 3,5-DBCat/3,5-DBSq-fixed Co^II/III entities. Complexes <b>1</b>·<i>S</i> and <b>2</b>·<i>S</i> could retain the crystallinity during desolvation, and the crystal structures of <b>1</b> and <b>2</b> were therefore able to be determined. Only when <b>1</b>·<i>S</i> and <b>2</b>·<i>S</i> desolvated above 310 K did the magnetic susceptibilities × temperatures values of the two complexes rise sharply, and then thermally induced complete, one-step VT transitions for <b>1</b> and <b>2</b> were available and repeatable. Complex <b>3</b>·<i>S</i> showed an incomplete, one-step VT transition independent of solvent molecules. Among these complexes, only <b>1</b> was sensitive to photoexcitation at low temperature, its photoinduced metastable state relaxed with temperature-independent behavior at low temperature range (5–10 K) and with thermally assisted behavior at high temperature range (above 20 K), respectively

Co-ligand and Solvent Effects on the Spin-Crossover Behaviors of PtS-type Porous Coordination Polymers

In our previous work (Chen, X.-Y.; Chem. Commun. 2013, 49, 10977−10979), we have reported the crystal structure and spin-crossover properties of a compound [Fe­(NCS)₂­(tppm)]·<i>S</i> [<b>1</b>·<i>S</i>, tppm = 4,4′,4″,4‴-tetrakis­(4-pyridyl­ethen-2-yl)­tetraphenylmethane, <i>S</i> = 5CH₃OH·​2CH₂Cl₂]. Here, its analogues [Fe­(X)₂­(tppm)]·<i>S</i> [X = NCSe^–, NCBH₃^–, and N­(CN)₂^– for compounds <b>2</b>·<i>S</i>, <b>3</b>·<i>S</i>, and <b>4</b>·<i>S</i>, respectively] have been synthesized and characterized by variable-temperature X-ray diffraction and magnetic measurements. The crystal structure analyses of <b>2</b>·<i>S</i> and <b>3</b>·<i>S</i> reveal that both compounds possess the same topologic framework (PtS-type) building from the tetrahedral ligand tppm and planar unit FeX₂; the framework is two-fold self-interpenetrated to achieve one-dimensional open channels occupied by solvent molecules. Powder X-ray diffraction study indicates the same crystal structure for <b>4</b>. The average values of Fe–N distances observed, respectively, at 100, 155, and 220 K for the Fe1/Fe2 centers are 1.969/2.011, 1.970/2.052, and 2.098/2.136 Å for <b>2</b>·<i>S</i>, whereas those at 110, 175, and 220 K are 1.972/2.013, 1.974/2.056, and 2.100/2.150 Å for <b>3</b>·<i>S</i>, indicating the presence of a two-step spin crossover in both compounds. Temperature-dependent magnetic susceptibilities (χ_M<i>T</i>) confirm the two-step spin-crossover behavior at 124 and 200 K in <b>2</b>·<i>S</i>, 151 and 225 K in <b>3</b>·<i>S</i>, and 51 and 126 K in <b>4</b>·<i>S</i>, respectively. The frameworks of <b>2</b>–<b>4</b> are reproducible upon solvent exchange and thereafter undergo solvent-dependent spin-crossover behaviors

A Dihalide–Decahydrate Cluster of [X₂(H₂O)₁₀]^2– in a Supramolecular Architecture of {[Na₂(H₂O)₆(H₂O@TMEQ[6])]·2(C₆H₅NO₃)}X₂(H₂O)₁₀ (TMEQ[6] = α,α′,δ,δ′-Tetramethylcucurbit[6]uril; X = Cl, Br)

A discrete dihalide–decahydrate cluster of [X₂­(H₂O)₁₀]^2– has been observed in a solid-state structure of {[Na₂­(H₂O)₆­(H₂O­@­TMEQ­[6])]·2­(C₆H₅­NO₃)}­X₂­(H₂O)₁₀} (TMEQ[6] = α,α′,δ,δ′-tetra­methyl­cucurbit[6]­uril; X = Cl (<b>1</b>), Br (<b>2</b>)). Its structure can be viewed as a connection of two [X­(H₂O)₃]⁻ clusters with a uudd water tetramer through hydrogen-bonding interactions

A Dihalide–Decahydrate Cluster of [X₂(H₂O)₁₀]^2– in a Supramolecular Architecture of {[Na₂(H₂O)₆(H₂O@TMEQ[6])]·2(C₆H₅NO₃)}X₂(H₂O)₁₀ (TMEQ[6] = α,α′,δ,δ′-Tetramethylcucurbit[6]uril; X = Cl, Br)

A discrete dihalide–decahydrate cluster of [X₂­(H₂O)₁₀]^2– has been observed in a solid-state structure of {[Na₂­(H₂O)₆­(H₂O­@­TMEQ­[6])]·2­(C₆H₅­NO₃)}­X₂­(H₂O)₁₀} (TMEQ[6] = α,α′,δ,δ′-tetra­methyl­cucurbit[6]­uril; X = Cl (<b>1</b>), Br (<b>2</b>)). Its structure can be viewed as a connection of two [X­(H₂O)₃]⁻ clusters with a uudd water tetramer through hydrogen-bonding interactions

A Dihalide–Decahydrate Cluster of [X₂(H₂O)₁₀]^2– in a Supramolecular Architecture of {[Na₂(H₂O)₆(H₂O@TMEQ[6])]·2(C₆H₅NO₃)}X₂(H₂O)₁₀ (TMEQ[6] = α,α′,δ,δ′-Tetramethylcucurbit[6]uril; X = Cl, Br)

A discrete dihalide–decahydrate cluster of [X₂­(H₂O)₁₀]^2– has been observed in a solid-state structure of {[Na₂­(H₂O)₆­(H₂O­@­TMEQ­[6])]·2­(C₆H₅­NO₃)}­X₂­(H₂O)₁₀} (TMEQ[6] = α,α′,δ,δ′-tetra­methyl­cucurbit[6]­uril; X = Cl (<b>1</b>), Br (<b>2</b>)). Its structure can be viewed as a connection of two [X­(H₂O)₃]⁻ clusters with a uudd water tetramer through hydrogen-bonding interactions

A Dihalide–Decahydrate Cluster of [X₂(H₂O)₁₀]^2– in a Supramolecular Architecture of {[Na₂(H₂O)₆(H₂O@TMEQ[6])]·2(C₆H₅NO₃)}X₂(H₂O)₁₀ (TMEQ[6] = α,α′,δ,δ′-Tetramethylcucurbit[6]uril; X = Cl, Br)

A discrete dihalide–decahydrate cluster of [X₂­(H₂O)₁₀]^2– has been observed in a solid-state structure of {[Na₂­(H₂O)₆­(H₂O­@­TMEQ­[6])]·2­(C₆H₅­NO₃)}­X₂­(H₂O)₁₀} (TMEQ[6] = α,α′,δ,δ′-tetra­methyl­cucurbit[6]­uril; X = Cl (<b>1</b>), Br (<b>2</b>)). Its structure can be viewed as a connection of two [X­(H₂O)₃]⁻ clusters with a uudd water tetramer through hydrogen-bonding interactions

Anion-Controlled Assembly of Silver(I)/Aminobenzonitrile Compounds: Syntheses, Crystal Structures, and Photoluminescence Properties

Five coordination compounds (CCs) of the formulas {[Ag­(<i>m</i>-abn)₂]·NO₃}_<i>n</i> (<b>1</b>), {[Ag₂(<i>m</i>-abn)₆]·(ClO₄)₂} (<b>2</b>), {[Ag­(<i>o</i>-abn)₂]·NO₃}_<i>n</i> (<b>3</b>), [Ag­(<i>o</i>-abn)₂(NO₂)]_<i>n</i> (<b>4</b>), and {[Ag­(<i>o</i>-abn)₂]·PF₆}_<i>n</i> (<b>5</b>) (<i>m</i>-abn = 3-aminobenzonitrile, and <i>o</i>-abn = 2-aminobenzonitrile) were synthesized and structurally characterized by element analysis, IR, powder X-ray diffraction, and X-ray single-crystal diffraction. Structural analysis reveals that aminobenzonitrile acts as bidentate μ₂-N,N′ or monodentate μ₁-N ligands in <b>1</b>–<b>5</b>. Complex <b>1</b> is a 1D chain comprised of <i>C</i>₂-symmetric [Ag­(<i>m</i>-abn)]₂ 14-membered rings. The uncoordinated NO₃^– anions interact with the 1D chain to form a resulting 2D supramolecular sheet through N–O···N hydrogen bond. Complex <b>2</b> is a discrete binuclear Ag­(I) CC incorporating concurrent bidentate μ₂-N,N′ and monodentate μ₁-N <i>m</i>-abn ligands. The variation of anions from NO₃^– to ClO₄^– results in the dimensionalities of <b>1</b> and <b>2</b> decreasing from 1D to 0D. When using <i>o</i>-abn, complexes <b>3</b>–<b>5</b> are obtained as 1D chain with <i>C</i>₂-symmetric [Ag­(<i>o</i>-abn)]₂ 12-membered rings, 2D sheet with coordinated μ₂-η¹:η² NO₂^– anions, and 1D chain with centrosymmetric [Ag­(<i>o</i>-abn)]₂ 12-membered rings, respectively. Supramolecular interactions such as hydrogen bonding and π···π stacking are also proven effective in shaping the dimensionalities of the solid state structures of <b>1</b>–<b>5</b>. Our results demonstrate that the anions are driving forces for the selection of different structures. Moreover, results about emissive behaviors and thermal stabilities of them are discussed

A Dihalide–Decahydrate Cluster of [X₂(H₂O)₁₀]^2– in a Supramolecular Architecture of {[Na₂(H₂O)₆(H₂O@TMEQ[6])]·2(C₆H₅NO₃)}X₂(H₂O)₁₀ (TMEQ[6] = α,α′,δ,δ′-Tetramethylcucurbit[6]uril; X = Cl, Br)

A discrete dihalide–decahydrate cluster of [X₂­(H₂O)₁₀]^2– has been observed in a solid-state structure of {[Na₂­(H₂O)₆­(H₂O­@­TMEQ­[6])]·2­(C₆H₅­NO₃)}­X₂­(H₂O)₁₀} (TMEQ[6] = α,α′,δ,δ′-tetra­methyl­cucurbit[6]­uril; X = Cl (<b>1</b>), Br (<b>2</b>)). Its structure can be viewed as a connection of two [X­(H₂O)₃]⁻ clusters with a uudd water tetramer through hydrogen-bonding interactions