Chemical CO2 fixation using a cyanido bridged heterometallic Zn(II)-Mn(II) 2D coordination polymer.

A new cyanido bridged Zn(II)-Mn(II) mixed-metal coordination polymer, {[Zn(µ-L)(µ-CN)2Mn0.5]·(CH3OH)}n (1), has been synthesized by the reaction of Zn(CN)2, Mn(II) salts and a hydrazone ligand (HL = (E)-N'-(phenyl(pyridin-2-yl)methylene)isonicotinohydrazide) in methanol. Compound 1 was characterized using various analytical methods (including elemental analysis, photoluminescence, FT-IR, XRD, SEM, and EDX analyses, and TGA), and its structure was determined by X-ray analysis. These analyses confirmed the formation of a mixed metal Zn(II)-Mn(II) coordination polymer containing both cyanide and hydrazone bridging ligands. This mixed metal coordination polymer exhibits interesting emission spectra by having several emissions via excitation at 230, 270, 375 and 385 nm. The catalytic activity of compound 1 in chemical CO2 fixation was investigated in the presence of epoxides, and the effects of various parameters on its catalytic performance were evaluated. The results of catalytic studies show that compound 1 can efficiently catalyze the chemical CO2 fixation reaction under mild conditions. The amount of co-catalyst, temperature of the reaction, nature of the solvent and also the substituent connected to the epoxide ring are some of the important parameters that have considerable effects on the catalytic activity of 1.

Difluorenoheteroles: topological control of π conjugation in diradicaloids and mixed-valence radical ions.

Two families of difluorenoheterole diradicaloids were synthesized, featuring isomeric ring systems with distinct conjugation topologies. The two types of difluorenoheteroles contain, respectively, a Chichibabin-like motif (CH) and a newly introduced heteroatom-linked triphenylmethyl dyad (TD-X). Combined experimental and theoretical investigations show that the TD-X systems have reduced quinoidal character but the interaction between formal spin centers is sufficiently strong to ensure a singlet ground state. The singlet-triplet energy gaps in the TD-X difluorenoheteroles are strongly affected by the heterocyclic ring, with values of -4.3 and -0.7 kcal mol-1 determined for the pyrrole- and thiophene-containing analogues, respectively. In cyclic voltammetry experiments, the TD-X systems show diminished energy gaps and superior reversibility in comparison with their CH counterparts. The radical anions and cations obtained from these diradicaloids show extremely red-shifted bands, occasionally with λ max > 3500 nm. Computational studies show that some of these ions adopt distonic structures and may be characterized as class-II mixed-valence species.

Cori Ester as the Ligand for Monovalent Cations.

Gerty T. and Carl F. Cori discovered, during research on the metabolism of sugars in organisms, the important role of the phosphate ester of a simple sugar. Glucose molecules are released from glycogen-the glucose stored in the liver-in the presence of phosphates and enter the blood as α-D-glucose-1-phosphate (Glc-1PH2). Currently, the crystal structure of three phosphates, Glc-1PNa2·3.5·H2O, Glc-1PK2·2H2O, and Glc-1PHK, is known. Research has shown that reactions of Glc-1PH2 with carbonates produce new complexes with ammonium ions [Glc-1P(NH4)2·3H2O] and mixed complexes: potassium-sodium and ammonium-sodium [Glc-1P(X)1.5Na0.5·4H2O; X = K or NH4]. The crystallization of dicationic complexes has been carried out in aqueous systems containing equimolar amounts of cations (1:1; X-Na). It was found that the first fractions of crystalline complexes always had cations in the ratio 3/2:1/2. The second batch of crystals obtained from the remaining mother liquid consisted either of the previously studied Na+, K+ or NH4+ complexes, or it was a new sodium hydrate-Glc-1PNa2·5·H2O. The isolated ammonium-potassium complex shows an isomorphic cation substitution and a completely unique composition: Glc-1PH(NH4)xK1-x (x = 0.67). The Glc-1P2- ligand has chelating fragments and/or bridging atoms, and complexes containing one type of cation show different modes of coordinating oxygen atoms with cations. However, in the case of the potassium-sodium and ammonium-sodium structures, high structural similarities are observed. The 1D and 2D NMR spectra showed that the conformation of Glc-1P2- is rigid in solution as in the solid state, where only rotations of the phosphate group around the C-O-P bonds are observed.

Recycling primary lithium batteries using a coordination chemistry approach: recovery of lithium and manganese residues in the form of industrially important materials.

In this study, we have investigated the potential use of post-consumer primary lithium metal batteries (LMBs) commonly used in portable electronic devices to recover lithium and manganese in the form of industrially important materials. A direct reaction of lithium-containing electronic waste with a naturally sourced ester, methyl salicylate, combined with a wide range of aliphatic alcohols has been used as a general method for recovering lithium in the form of lithium aryloxides of different nuclearities [Li(OAr)(HOMe)2] (1), [Li(OAr)(HOAr)] (2), [Li(OAr)(HOEt)]2 (3), [Li(OAr)(H2O)]2 (4), [Li4(OAr)4(EGME)2] (5), [Li6(OAr)6] (6-8) for ArOH = methyl salicylate (1, 2, 4, 6), ethyl salicylate (3, 7), 2-methoxyethyl salicylate (5, 8), and EGME = 2-methoxyethanol. The hydrolysis of 7 was then used to synthesize lithium salicylate [Li(Sal)(H2O)]n (10), which is an important antioxidant in the production of oils and grease. The discharged cathode material of Li-MnO2 batteries was investigated as a source from which LiClO4, Li2CO3, LiMn2O4, and Mn2O3 can be recovered by means of water-alcohol extraction or calcination. Particular emphasis was placed on the detailed characterization of all battery components and their decomposition products. LMBs were completely recycled for the first time, and materials were recovered from the cathode and the anode.

Hierarchical Self-Assembly of Curved Aromatics: From Donor-Acceptor Porphyrins to Triply Periodic Minimal Surfaces.

A saddle-shaped π-extended zinc porphyrin containing a peripheral pyridyl ligand undergoes quantitative self-assembly into a cyclic trimer. The trimer has a prismatic structure with negatively curved side walls, which promote the formation of supramolecular organic frameworks stabilized by dispersion interactions. The first framework type, UWr-1, has the npo topology, with a hexagonal structure analogous to the Schwartz H triply periodic minimal surface. Co-crystallization of the trimer with either C60 and C70 produces the isomorphous cubic UWr-2 and UWr-3 phases, characterized by the ctn network topology and a structural relationship to the Fischer-Koch minimal surface S. All three phases contain complex labyrinths of solvent-filled channels, corresponding to very large probe-accessible volumes (68 % to 76 %). The UWr-2 network could be partly desolvated while retaining its long range dimensional order, indicating remarkable strength of the dispersion interactions in the crystal. A theoretical analysis of noncovalent interactions shows the role of geometrical matching between the negatively curved porphyrin units and positively curved fullerenes.

Tetrafluorenofulvalene as a sterically frustrated open-shell alkene.

Electronic and steric effects are known to greatly influence the structure, characteristics and reactivity of organic compounds. A typical π bond is weakened by oxidation (corresponding to the removal of electrons from bonding orbitals), by reduction (through addition of electrons to antibonding orbitals) and by unpairing of the bonding electrons, such as in the triplet state. Here we describe tetrafluorenofulvalene (TFF), a twisted, open-shell alkene for which these general rules do not hold. Through the synthesis, experimental characterization and computational analysis of its charged species spanning seven redox states, the central alkene bond in TFF is shown to become substantially stronger in the tri- and tetraanion, generated by chemical reduction. Furthermore, although its triplet state contains a weaker alkene bond than the singlet, in the quintet state its bond order increases substantially, yielding a flatter structure. This behaviour originates from the doubly bifurcated topology of the underlying spin system and can be rationalized by the balancing effects of benzenoid aromaticity and spin pairing.

Dinor[7]helicene and Beyond: Divergent Synthesis of Chiral Diradicaloids with Variable Open-Shell Character.

Diradicaloid helicenes constructed formally by non-benzenoid double π-extension of phenanthrene were synthesized by a common strategy involving double electrophilic benzannulation. Steric effects in the second benzannulation step led to considerable structural diversity among the products, yielding a symmetrical dinor[7]helicene 1 and two isomeric unsymmetrical double helicenes 2 and 3, containing a nor[5]helicene and [4]helicene fragment, respectively, in addition to a common nor[6]helicene motif. Geometries, configurational dynamics, and electronic structure of these helicenes were analyzed using solid-state structures, spectroscopic methods, and computational analyses. The open-shell character of the singlet states of these helicenes increases in the order 3<1<2, with strongly varying diradicaloid indexes and singlet-triplet gaps. Compounds 1-3 displayed narrow optical gaps of 0.79-1.25 eV, resulting in significant absorption in the near infrared (NIR) region. They also exhibit reversible redox chemistry, each of them yielding stable radical cations, radical anions, and dianions, in some cases possessing intense NIR absorptions extending beyond 2500 nm.

Synthesis, Crystal Structures, and Optical and Magnetic Properties of Samarium, Terbium, and Erbium Coordination Entities Containing Mono-Substituted Imine Silsesquioxane Ligands.

Mono-substituted cage-like silsesquioxanes of the T8-type can play the role of potential ligands in the coordination chemistry. In this paper, we report on imine derivatives as ligands for samarium, terbium, and erbium cations and discuss their efficient synthesis, crystal structures, and magnetic and optical properties. X-ray analysis of the lanthanide coordination entities [MCl3(POSS)3]·2THF [M = Er3+ (3), Tb3+ (4), Sm3+ (5)] showed that all three compounds crystallize in the same space group with similar lattice parameters. All compounds contain an octahedrally coordinated metal atom, and additionally, 3 and 5 structures are strictly isomorphous. However, surprisingly, there are two different molecules in the crystal structure of the terbium coordination entity 4, monomer (sof 65%) and dimer (sof 35%), with one and two metal centers. Absorption measurements of the investigated materials recorded at 300 K showed that regardless of the lanthanide involved, their energy band gap equals 2.7 eV. Moreover, the analogues containing Tb3+ and Sm3+ exhibit luminescence typical of these rare earth ions in the visible and infrared spectral range, while the compound with Er3+ does not generate any emission. Direct current variable-temperature magnetic susceptibility measurements on polycrystalline samples of 3-5 were performed between 1.8 and 300 K. The magnetic properties of 3 and 4 are dominated by the crystal field effect on the Er3+ and Tb3+ ions, respectively, hiding the magnetic influence between the magnetic cations of adjacent molecules. Complex 5 exhibits a nature typical for the paramagnetism of the samarium(III) cation.

Heterometallic 3d-4f Alkoxide Precursors for the Synthesis of Binary Oxide Nanomaterials.

In this study, a new method for the synthesis of heterometallic 3d-4f alkoxides by the direct reaction of metallic lanthanides (La, Pr, Nd, Gd) with MCl2 (M = Mn, Ni, Co) in 2-methoxyethanol was developed. The method was applied to the synthesis of the heterometallic oxo-alkoxide clusters [Ln4Mn2(µ6-O)(µ3-OR)8(HOR)xCl6] (Ln = La (1), Nd (2), Gd (3); x = 0, 2, 4); [Pr4M2(µ6-O)(µ3-OR)8(HOR)xCl6] (M = Co (4), Ni (5); x = 2, 4); and [Ln4Mn2(µ3-OH)2(µ3-OR)4(µ-OR)4(µ-Cl)2(HOR)4Cl6] (Ln = La (11) and Pr (12)). Mechanistic investigation led to the isolation of the homo- and heterometallic intermediates [Pr(µ-OR)(µ-Cl)(HOR)Cl]n (6), [Co4(µ3-OR)4(HOR)4Cl4] (7), [Ni4(µ3-OR)4(HOEt)4Cl4] (8), [Mn4(µ3-OR)4(HOR)2(HOEt)2Cl4] (9), and [Nd(HOR)4Cl][CoCl4] (10). In the presence of an external M(II) source at 1100 °C, 1-4 and 12 were selectively converted into binary metal oxide nanomaterials with trigonal or orthorhombic perovskite structures, i.e., LaMnO3, GdMnO3, NdMnO3, Pr0.9MnO3, and PrCoO3. Compound 5 decomposed into a mixture of homo- and heterometallic oxides. The method presented provides a valuable platform for the preparation of advanced heterometallic oxide materials with promising magnetic, luminescence, and/or catalytic applications.

Green carbon-carbon homocoupling of terminal alkynes by a silica supported Cu(II)-hydrazone coordination compound.

A Cu(II) complex, [Cu(HL)(NO3)(CH3OH)]·CH3OH (1), was obtained by the reaction of Cu(NO3)2·3H2O and H2L in methanol solvent (H2L is (E)-4-amino-N'-(2-hydroxy-3-methoxybenzylidene)benzohydrazide). H2L and compound 1 were characterized by various spectroscopic analyses and the molecular structure of [Cu(HL)(NO3)(CH3OH)]·CH3OH was determined by single-crystal X-ray analysis. The results indicated the product is a mononuclear Cu(II) complex and contains a free NH2 functional group on the structure of the ligand. [Cu(HL)(NO3)(CH3OH)]·CH3OH was used for the preparation of a heterogeneous catalyst by supporting it on functionalized silica gel. The heterogeneous catalyst (Si-Cu) was prepared by an amidification reaction of [Cu(HL)(NO3)(CH3OH)]·CH3OH with functionalized silica gel. The resulting silica-supported catalyst (Si-Cu) was characterized by TGA, FT-IR, EPR, DRS, EDS, XRD, SEM and XPS analyses. Si-Cu was employed in a carbon-carbon coupling reaction and the effects of the amount of Si-Cu and temperature were investigated in the catalytic coupling. The structure of one of the products of the catalytic reactions (C16H22O2, CP1) was determined by single-crystal X-ray analysis, which proved the formation of a C-C bond and the production of di-acetylene by homocoupling of terminal alkyne. This catalytic system is stable and it can be reused for a coupling reaction without a significant change in its catalytic activity.

A copper(II) coordination compound under water-oxidation reaction at neutral conditions: decomposition on the counter electrode.

In the context of energy storage, the oxygen-evolution reaction (OER, 2H2O → O2 + 4H+ + 4e-) through the water-oxidation reaction is a thermodynamically uphill reaction in overall water splitting. In recent years, copper(II) coordination compounds have been extensively used for the OER. However, challenges remain in finding the mechanism of the OER in the presence of these metal coordination compounds. Herein, the electrochemical OER activity is investigated in the presence of a copper(II) coordination compound at pH ≈ 7. While the investigations on finding true catalysts for the OER are focused on the working electrode, herein, for the first time, the focus is on the decomposition of copper(II) coordination compound (CuL3, L: 2,2'-bipyridine N,N'-dioxide) during the OER on the counter electrode toward the precipitation of copper(I) oxide and metallic Cu.

Tridecacyclene Tetraimide: An Easily Reduced Cyclooctatetraene Derivative.

Tridecacyclene tetraimide, TCTI, an electron-deficient non-benzenoid nanocarbon with a C56 N4 polycyclic framework was obtained in a concise synthesis. TCTI has a non-planar structure and forms π-stacked dimers in the solid state. In solution, it undergoes eight single-electron reductions, yielding a range of negatively charged states up to an octaanion. Except for the latter species, which has a remarkably large electronic gap, the anions feature extended near-infrared absorptions, with a particularly strong band at 1692 nm observed for the dianion. A computational analysis of the TCTI anions shows that their stability originates from the combined effects of electron-deficient imide groups and the local aromaticity of reduced acenaphthylene units. The properties of TCTI make it potentially useful in electrochromic and charge storage applications.

Water oxidation reaction in the presence of a dinuclear Mn(II)-semicarbohydrazone coordination compound.

Water splitting, producing of oxygen, and hydrogen molecules, is an essential reaction for clean energy resources and is one of the challenging reactions for artificial photosynthesis. The Mn4Ca cluster in photosystem II (PS-II) is responsible for water oxidation in natural photosynthesis. Due to this, water oxidation reaction by Mn coordination compounds is vital for mimicking the active core of the oxygen-evolving complex in PS-II. Here, a new dinuclear Mn(II)-semicarbohydrazone coordination compound, [Mn(HL)(µ-N3)Cl]2 (1), was synthesized and characterized by various methods. The structure of compound 1 was determined by single crystal X-ray analysis, which revealed the Mn(II) ions have distorted octahedral geometry as (MnN4OCl). This geometry is created by coordinating of oxygen and two nitrogen donor atoms from semicarbohydrazone ligand, two nitrogen atoms from azide bridges, and chloride anion. Compound 1 was used as a catalyst for electrochemical water oxidation, and the surface of the electrode after the reaction was investigated by scanning electron microscopy, energy dispersive spectrometry, and powder X-ray diffraction analyses. Linear sweep voltammetry (LSV) experiments revealed that the electrode containing 1 shows high activity for chemical water oxidation with an electrochemical overpotential as low as 377 mV. Although our findings showed that the carbon paste electrode in the presence of 1 is an efficient electrode for water oxidation, it could not withstand water oxidation catalysis under bulk electrolysis and finally converted to Mn oxide nanoparticles which were active for water oxidation along with compound 1.

Use of heterometallic alkali metal-magnesium aryloxides in ring-opening polymerization of cyclic esters.

In this work, alkali metal-magnesium aryloxides [Mg2Li2(MesalO)6] (1), [Mg2Na2(MesalO)6(THF)x] for x = 2 or 4 (2), and [Mg2K2(MesalO)6(THF)4] (3) derived from the reaction of MgnBu2 and nBuLi, metallic Na or K with methyl salicylate (MesalOH) were used as molecular platforms for the synthesis of new heterometallic compounds [Mg2Li2(EtsalO)6] (4), [MgK(EtsalO)3]n (5), [Mg6Na4Al(MesalO)13(OH)6(MesalOH)(THF)0.5(H2O)0.5] (6), and [Mg4Na2(MesalO)6(SalO)2(THF)4] (7) (EtsalOH = ethyl salicylate and SalOH2 = salicylic acid) by the reaction with EtOH, exposure to atmospheric moisture or addition of stoichiometric quantities of water. Compounds 4 and 5 were synthesized by transesterification of 1 and 3. Cluster 6 was formed haphazardly by exposing a THF solution of 2 derived using MgnBu2 stabilized with 1 wt% AlEt3 to atmospheric moisture. Compound 7 was synthesized by partial hydrolysis of 2. Homometallic magnesium aryloxide [Mg4(MesalO)4(OMe)4(HOMe)4] (8) was obtained by reaction of MgnBu2 and MesalOH in a methanol solution. The catalytic activity of 1-3 and 6-8 was investigated in the ring-opening polymerization (ROP) of L-lactide (L-LA) or benzaldehyde Tishchenko reaction.

Synthesis of a donor-acceptor heterodimer via trifunctional completive self-sorting.

Selective self-assembly of heterodimers consisting of two non-identical subunits plays important roles in Nature but is rarely encountered in synthetic supramolecular systems. Here we show that photocleavage of a donor-acceptor porphyrin complex produces an heterodimeric structure with surprising selectivity. The system forms via a multi-step sequence that starts with an oxidative ring opening, which produces an equimolar mixture of two isomeric degradation products (zinc(II) bilatrien-abc-ones, BTOs). These two isomers are susceptible to water addition, yielding the corresponding zinc(II) 15-hydroxybiladien-ab-ones (HBDOs). However, in the photocleavage experiment only one HBDO isomer is formed, and it quantitatively combines with the remaining BTO isomer. The resulting heterodimer is stabilized by a Zn-O coordination bond and extended dispersion interactions between the overlapping π-surfaces of the monomers. The observed selectivity can be seen as a case of completive self-sorting, simultaneously controlled by three types of complementary interactions.

Green solvent free epoxidation of olefins by a heterogenised hydrazone-dioxidotungsten(vi) coordination compound.

A new mononuclear tungsten coordination compound, [WO2L(CH3OH)] (1), was synthesized by the reaction of WCl6 and H2L (H2L = (E)-4-amino-N'-(5-bromo-2-hydroxybenzylidene)benzohydrazide) in methanol. Both the H2L and compound 1 were characterized by elemental analysis and UV-Vis, FT-IR and NMR spectroscopic methods. The molecular structure of compound 1 was also determined by single crystal X-ray analysis which confirmed the compound is a mononuclear coordination compound of cis-dioxidotungsten(vi) containing a free amine functionality on the ligand. Compound 1 was supported on propionyl chloride-functionalized silica gel by amidification reaction to obtain a heterogeneous catalyst. The obtained heterogeneous catalyst was characterized by FT-IR spectroscopy, thermal gravimetric analysis (TGA), diffuse-reflectance spectroscopy (DRS), X-ray diffraction analysis (XRD), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) and its catalytic activity was investigated in the epoxidation of olefins with hydrogen peroxide under solvent free conditions. The catalyst was successfully recovered several times and the recovered catalyst was also characterized by various methods including FT-IR, DRS, TGA, SEM and EDX analyses. The results indicated this heterogeneous catalytic system is an effective and selective catalyst for epoxidation of olefins and can be reused several times without significant change in its catalytic activity.

Naphthalimide-Fused Dipyrrins: Tunable Halochromic Switches and Photothermal NIR-II Dyes.

A family of tunable halochromic switches is developed using a naphthalimide-fused dipyrrin as the core π-conjugated motif. Electronic properties of these dipyrrins are tuned by substitution of their alpha and meso positions with aryl groups of variable donor-acceptor strength. The first protonation results in a conformational change that enhances electronic coupling between the dipyrrin chromophore and the meso substituent, leading to halochromic effects that occasionally exceed 200 nm and switch the absorption between the near-infrared (NIR)-I and NIR-II ranges. A NIR-II photothermal effect, switchable by acid-base chemistry is demonstrated for selected dipyrrins. Further protonation is possible for derivatives bearing additional amino groups, leading to up to four halochromic switching step. The most electron-rich dipyrrins are also susceptible to chemical oxidation, yielding NIR-absorbing radical cations and closed-shell dications.

Helicity Modulation in NIR-Absorbing Porphyrin-Ryleneimides.

Peripheral substitution of a π-extended porphyrin with bulky groups produces a curved chromophore with four helical stereogenic units. The curvature and stereochemistry of such porphyrins can be controlled by varying the substituents, coordinated metal ions, and apical ligands. In particular, when the achiral saddle-shaped free bases are treated with large metal ions, i.e., CdII or HgII , the resulting complexes convert to chiral propeller-like configurations. X-ray diffraction analyses show that apical coordination of a water molecule is sufficient to induce a notable bowl-like distortion of the cadmium complex, which however retains its chiral structure. For phenyl- and tolyl-substituted derivatives, the conversion is thermodynamically controlled, whereas complexes bearing bulky 4-(tert-butyl)phenyl groups transform into their chiral forms upon heating. In the latter case, the chiral Hg porphyrin was converted into the corresponding free base and other metal complexes without any loss of configurational purity, ultimately providing access to stable, enantiopure porphyrin propellers.

Use of group 13 aryloxides for the synthesis of green chemicals and oxide materials.

In this work, group 13 metal aryloxides [Al(MesalO)3] (1), [Me2Ga(MesalO)]2 (2), [AlLi3(MesalO)6] (3) and [Me2GaLi(MesalO)2(THF)] (4) were obtained by the reaction of methyl salicylate (MesalOH) with group-13 alkyls MMe3 (for M = Al, Ga) or their combination with BuLi in a THF/alcohol solution. The direct reaction of MMe3 (for M = Al, Ga) and MesalOH (1 : 3) led to compound 1 or 2, respectively. When the same reactions were carried out with additional BuLi, the heterometallic compound 3 or the mixture of 4 and [Li6(MesalO)6] (5) was obtained. Compounds 1-5 were used for the chemical conversion of glycerol to α-hydroxy acid glyceryl esters by alcoholysis of L-lactide (L-LA), glycolide (GA), and ε-caprolactone (ε-CL). Compounds 1-5 were also efficient initiators for the ring-opening polymerization (ROP) of L-LA, GA, and ε-CL using glycerol as a branching agent to synthesize 3-arm polyesters. Heterometallic compounds 3 and 4 were attractive molecular precursors for the preparation of group 13-lithium ceramics, i.e. γ-LiAlO2 and ß-LiGaO2.

Acenaphtho[1,2-d][1,2,3]triazole and Its Kuratowski Complex: A π-Extended Tecton for Supramolecular and Coordinative Self-Assembly.

π-Extended acenaphtho[1,2-d][1,2,3]triazoles, the unsubstituted Anta-H and its di-tert-butyl derivative Dibanta-H, as well as 5,6,7,8-tetrahydro-1H-naphtho[2,3-d][1,2,3]triazole Cybta-H were obtained in concise syntheses. In the solid state, Dibanta-H forms an unprecedented hydrogen-bonded cyclic tetrad, stabilized by dispersion interactions of the bulky tBu substituents, whereas a cyclic triad was found in the crystal structure of Anta-H. These cyclic assemblies form infinite slipped stacks in the crystals. Evidence for analogous hydrogen-bonded self-assembly in solution was provided by low-temperature NMR spectroscopy and computational analyses. Kuratowski-type pentanuclear complexes [Zn5 Cl4 (Dibanta)6 ] and [Zn5 Cl4 (Cybta)6 ] were prepared from the respective triazoles. In the Dibanta complexes, the π-aromatic surfaces of the ligands extend from the edges of the tetrahedral Zn5 core, yielding an enlarged structure with significant internal molecular free volume and red-shifted fluorescence.