From Encapsulation to Polypseudorotaxane: Unusual Anion Networks Driven by Predesigned Metal Bis(terpyridine) Complex Cations

[Ru3(CN)3(CO)9]3-: Building Block for Multimetallic Cages

A cluster-ligand is disclosed in the form of [Ru3(CN)3(CO)9]3- ([1]3-). Produced by simple reaction of [Ru3(CO)12] with cyanide, [1]3- serves as a precursor to a series of μ-CN cages. When treated with [Ru3(CO)12], it readily forms the prism [Ru6(μ-CN)3(CO)18]3-. With 1.5 equiv of [Cu(MeCN)4]+ [1]3- reacts to give the expanded prism {Cu3[Ru3(μ-CN)3(CO)9]2}3-, which features three two-coordinate Cu(I) centers. Sources of Ni2+ and Fe2+ bind two equivalents of [1]3-, giving the double cages {M[Ru3(μ-CN)3(CO)9]2}4- (M = Ni, Fe) wherein the central metal is octahedral. The 1:1 reaction using [Fe(H2O)6]2+ gave the interpenetrated super-tetrahedrane {Fe4(μ4-O)[Ru3(μ-CN)3(CO)9]4}4-.

Terpyridine-Based 3D Metal-Organic-Frameworks: A Structure-Property Correlation

Design, synthesis, and applications of metal-organic frameworks (MOFs) are among the most salient fields of research in modern inorganic and materials chemistry. As the structure and physical properties of MOFs are mostly dependent on the organic linkers or ligands, the choice of ligand system is of utmost importance in the design of MOFs. One such crucial organic linker/ligand is terpyridine (tpy), which can adopt various coordination modes to generate an enormous number of metal-organic frameworks. These frameworks generally carry physicochemical characteristics induced by the π-electron-rich (basically N-electron-rich moiety) terpyridines. In this minireview, the construction of 3D MOFs associated with symmetrical terpyridines is discussed. These ligands can be easily derivatized at the lateral phenyl (4'-phenyl) position and incorporate additional organic functionalities. These functionalities lead to some different binding modes and form higher dimensional (3D) frameworks. Therefore, these 3D MOFs can carry multiple features along with the characteristics of terpyridines. Some properties of these MOFs, like photophysical, chemical selectivity, photocatalytic degradation, proton conductivity, and magnetism, etc. have also been discussed and correlated with their frameworks.

A Chiral 3 D Net with 2 D Cairo Pentagonal Tiling Projection in Site-Modified CuCN/CuSCN Networks

A novel isohedral 3-periodic net (i.e. a net with one kind of tile), showing a Cairo pentagonal tiling projection on the Euclidean plane, has been identified in a series of site-modified CuCN/CuSCN networks, namely, [Cu₆ (SCN)₂ (CN)₆ ⋅Ni(tpy)₂ ]_n (1), [Cu₆ (SCN)(CN)₇ ⋅Ni(tpy)₂ ]_n (2) and [Cu₆ (CN)₈ ⋅Ni(tpy)₂ ]_n (3) (tpy=2,2':6'',2''-terpyridine). These infinite inclusion compounds were prepared via a solvothermal sulfur migration reaction with subtle modification to fine-tune the sulfur content. The chiroptical activity of single crystals, which arises from the intrinsically chiral net, was confirmed by X-ray diffraction and solid-state circular dichroism spectra.

Synthesis and structural characterization of a novel copper(II)/lead(II) heterometallic organic–inorganic hybrid

A new copper(II)/lead(II) complex [(terpy)3CuPb5Br12] (1) (terpy = 2,2′:6′,2″-terpyridine) has been synthesized and characterized by IR, elemental analysis, and single-crystal X-ray diffraction analysis. The copper(II) and lead(II) ions in the title complex are in distorted six- (Cu(II), Pb(II)) and eight-fold (Pb(II)) coordination environments, in which the donor atoms are provided by bromide anions and nitrogen atoms of the 2,2′:6′,2″-terpyridine ligands. Complex 1 contains [(terpy)4Pb9Br20]2– building blocks. These bromoplumbate(II) clusters are connected by (terpy)2Cu2Br4 units along the crystallographic b axis and by PbBr6 units along the a axis, thereby forming an extended sheet structure.

A lanthanide salen "square prism" and a wrapped exo-lanthanide salen "double decker"

An erbium(iii) salen "square prism" and a supramolecular aggregate of exo-erbium(iii) salen "double-decker" cations wrapped by an anionic cuprous cyanide network were prepared from N,N'-ethylene bis[4-(diethylamino)salicylideneimine. Both erbium(iii) edifices show fine-structure near-infrared (NIR) luminescence under the excitation in the visible light area. Here we provide a novel and efficient method for stabilizing non-isolable lanthanide edifices in the solid state.

Facile preparation and dual catalytic activity of copper(i)–metallosalen coordination polymers

Three copper(i)–metallosalen coordination polymers (CPs), {[Ni^II(SalImCy)]₂(Cu^ICN)₉}_n (1), {[Cu^II(SalImCy)]₂(Cu^ICN)₉}_n (2) and {[Ni^II(SalImCy)](Cu^II)₂·DMF}_n (3) were prepared by direct combination of Ni^II/Cu^II(salen) motifs with [Cu^ICN]_n chains and Cu₂I₂ clusters via the metalloligand strategy.

Water-chloride and water-bromide hydrogen-bonded networks: influence of the nature of the halide ions on the stability of the supramolecular assemblies

Two compounds, namely, [TTPH(2)](Cl)(2) x 4 H(2)O (1) and [TTPH(2)](Br)(2) x 4 H(2)O (2), (TTP = 4'-p-tolyl-2,2':6',2''-terpyridine) were synthesized from purely aqueous media and characterized by physical techniques. In the solid-state structures of these compounds, interesting supramolecular assemblies are observed. In 1, an unusual staircase-like architecture of the tape of edge-shared planar water hexamer is of importance, where the chloride ions are at the two edges of the tape. In 2, the polymeric nature of the water-bromide assembly is of interest, where discrete open-cube water octamers are doubly bridged by bromide ions. Semiempirical and DFT calculations confirm that the nature of the anion indeed affects the topology of the water-halide assemblies. We conclude that the protonated [TTPH(2)](2+) species can act as appropriate receptors for halide ions, which in turn act as a matrix for the formation of polymeric 1D water-halide assemblies.

pH-Induced formation of metalloligand: increasing structure dimensionality by tuning number of ligand functional sites

Two complexes, 2D [Cu(2)(CN)(2)(4-Hpcih)](n) and 3D [[Cu(2)(CN)(1.5)(4-pcih)].1.25H(2)O](n) (4-Hpcih = 4-pyridinecarbaldehyde isonicotinoyl hydrazone), were obtained using a synthetic approach of pH-induced formation of metalloligands, successfully demonstrating a strategy to increase structure dimensionality by tuning the number of ligand functional sites.