Self-Recognizing π-π Stacking Interactions Designed for the Generation of Ultrastable Mesoporous Hydrogen-Bonded Organic Frameworks

Creating crystalline porous materials with large pores is typically challenging due to undesired interpen-etration, staggered stacking, or weakened framework stability. Here, we report a pore size expansion strategy by self-recognizing π-π stacking interactions in a series of two-dimensional (2D) hydrogen–bonded organic frameworks (HOFs), HOF-10x (x=0,1,2), self-assembled from pyrene-based tectons with systematic elongation of π-conjugated molecular arms. This strategy successfully avoids interpene-tration or staggered stacking and expands the pore size of HOF materials to access mesoporous HOF-102, which features a surface area of ~ 2,500 m2/g and the largest pore volume (1.3 cm3/g) to date among all reported HOFs. More importantly, HOF-102 shows significantly enhanced thermal and chemical stability as evidenced by powder x-ray diffraction and N2 isotherms after treatments in chal-lenging conditions. Such stability enables the adsorption of dyes and cytochrome c from aqueous media by HOF-102 and affords a processible HOF-102/fiber composite for the efficient photochemical detox-ification of a mustard gas simulant.

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Isomeric 4,2′:6′,4″- and 3,2′:6′,3″-Terpyridines with Isomeric 4′-Trifluoromethylphenyl Substituents: Effects on the Assembly of Coordination Polymers with [Cu(hfacac)2] (Hhfacac = Hexafluoropentane-2,4-dione)

Inorganics ◽

10.3390/inorganics9070054 ◽

2021 ◽

Vol 9 (7) ◽

pp. 54

Author(s):

Giacomo Manfroni ◽

Simona S. Capomolla ◽

Alessandro Prescimone ◽

Edwin C. Constable ◽

Catherine E. Housecroft

Keyword(s):

Coordination Polymers ◽

Metal Binding ◽

Polymer Chains ◽

Stacking Interactions ◽

X Ray Diffraction ◽

Preparative Scale ◽

X Ray ◽

Single Crystal Structures ◽

Π Stacking ◽

Packing Interactions

The isomers 4′-(4-(trifluoromethyl)phenyl)-4,2′:6′,4″-terpyridine (1), 4′-(3-(trifluoromethyl)phenyl)-4,2′:6′,4″-terpyridine (2), 4′-(4-(trifluoromethyl)phenyl)-3,2′:6′,3″-terpyridine (3), and 4′-(3-(trifluoromethyl)phenyl)-3,2′:6′,3″-terpyridine (4) have been prepared and characterized. The single crystal structures of 1 and 2 were determined. The 1D-polymers [Cu2(hfacac)4(1)2]n.2nC6H4Cl2 (Hhfacac = 1,1,1,5,5,5-hexafluoropentane-2,4-dione), [Cu(hfacac)2(2)]n.2nC6H5Me, [Cu2(hfacac)4(3)2]n.nC6H4Cl2, [Cu2(hfacac)4(3)2]n.nC6H5Cl, and [Cu(hfacac)2(4)]n.nC6H5Cl have been formed by reactions of 1, 2, 3 and 4 with [Cu(hfacac)2].H2O under conditions of crystal growth by layering and four of these coordination polymers have been formed on a preparative scale. [Cu2(hfacac)4(1)2]n.2nC6H4Cl2 and [Cu(hfacac)2(2)]n.2nC6H5Me are zig-zag chains and the different substitution position of the CF3 group in 1 and 2 does not affect this motif. Packing of the polymer chains is governed mainly by C–F...F–C contacts, and there are no inter-polymer π-stacking interactions. The conformation of the 3,2′:6′,3″-tpy unit in [Cu2(hfacac)4(3)2]n.nC6H4Cl2 and [Cu(hfacac)2(4)]n.nC6H5Cl differs, leading to different structural motifs in the 1D-polymer backbones. In [Cu(hfacac)2(4)]n.nC6H5Cl, the peripheral 3-CF3C6H4 unit is accommodated in a pocket between two {Cu(hfacac)2} units and engages in four C–Hphenyl...F–Chfacac contacts which lock the phenylpyridine unit in a near planar conformation. In [Cu2(hfacac)4(3)2]n.nC6H4Cl2 and [Cu(hfacac)2(4)]n.nC6H5Cl, π-stacking interactions between 4′-trifluoromethylphenyl-3,2′:6′,3″-tpy domains are key packing interactions, and this contrasts with the packing of polymers incorporating 1 and 2. We use powder X-ray diffraction to demonstrate that the assemblies of the coordination polymers are reproducible, and that a switch from a 4,2′:6′,4″- to 3,2′:6′,3″-tpy metal-binding unit is accompanied by a change from dominant C–F...F–C and C–F...H–C contacts to π-stacking of arene domains between ligands 3 or 4.

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Construction of Two Stable Co(II)-Based Hydrogen-Bonded Organic Frameworks as a Luminescent Probe for Recognition of Fe3+ and Cr2O72− in H2O

Molecules ◽

10.3390/molecules26195955 ◽

2021 ◽

Vol 26 (19) ◽

pp. 5955

Author(s):

Qi-Ying Weng ◽

Ya-Li Zhao ◽

Jia-Ming Li ◽

Miao Ouyang

Keyword(s):

Detection Limit ◽

Aqueous Media ◽

Three Dimensional ◽

Cobalt Atom ◽

High Sensitivity ◽

X Ray Diffraction ◽

Chlorobenzoic Acid ◽

X Ray ◽

Highly Sensitive ◽

Hydrogen Bonded

A pair of cobalt(II)-based hydrogen-bonded organic frameworks (HOFs), [Co(pca)2(bmimb)]n (1) and [Co2(pca)4(bimb)2] (2), where Hpca = p-chlorobenzoic acid, bmimb = 1,3-bis((2-methylimidazol-1-yl)methyl)benzene, and bimb = 1,4-bis(imidazol-1-ylmethyl)benzene were hydrothermally synthesized and characterized through infrared spectroscopy (IR), elemental and thermal analysis (EA), power X-ray diffraction (PXRD), and single-crystal X-ray diffraction (SCXRD) analyses. X-ray diffraction structural analysis revealed that 1 has a one-dimensional (1D) infinite chain network through the deprotonated pca− monodentate chelation and with a μ2-bmimb bridge Co(II) atom, and 2 is a binuclear Co(II) complex construction with a pair of symmetry-related pca− and bimb ligands. For both 1 and 2, each cobalt atom has four coordinated twisted tetrahedral configurations with a N2O2 donor set. Then, 1 and 2 are further extended into three-dimensional (3D) or two-dimensional (2D) hydrogen-bonded organic frameworks through C–H···Cl interactions. Topologically, HOFs 1 and 2 can be simplified as a 4-connected qtz topology with a Schläfli symbol {64·82} and a 4-connected sql topology with a Schläfli symbol {44·62}, respectively. The fluorescent sensing application of 1 was investigated; 1 exhibits high sensitivity recognition for Fe3+ (Ksv: 10970 M−1 and detection limit: 19 μM) and Cr2O72− (Ksv: 12960 M−1 and detection limit: 20 μM). This work provides a feasible detection platform of HOFs for highly sensitive discrimination of Fe3+ and Cr2O72− in aqueous media.

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A zinc(II) coordination polymer based on a flexible bis(benzimidazole) ligand: synthesis, crystal structure and fluorescence study

Zeitschrift für Naturforschung B ◽

10.1515/znb-2020-0094 ◽

2020 ◽

Vol 75 (12) ◽

pp. 1005-1009

Author(s):

Geng Zhang ◽

Xinzhao Xia ◽

Jianhua Xu ◽

Lixian Xia ◽

Cong Wang ◽

...

Keyword(s):

Coordination Polymer ◽

Hydrothermal Reaction ◽

Emission Peak ◽

Stacking Interactions ◽

X Ray Diffraction ◽

Fluorescence Study ◽

One Dimensional ◽

X Ray ◽

Π Stacking ◽

Solid State Fluorescence

AbstractA new one-dimensional Zn(II) coordination polymer, {[ZnCl2(BBM)]·CH3OH}n (2,2-(1,4-butanediyl)bis-1,3-benzimidazole [BBM]), has been obtained from the hydrothermal reaction of zinc chloride with the flexible bis-benzimidazole ligand BBM and characterized by single-crystal X-ray diffraction, elemental analysis, IR and UV–vis spectra. Structural analysis has revealed that the BBM ligand connects the Zn(II) atoms to form a square-wave chain, which is further extended into supramolecular layers through hydrogen bonds and π···π stacking interactions. Solid-state fluorescence investigations showed that the Zn(II) coordination polymer has an emission peak at 381 nm upon excitation at 330 nm, which is attributed to ligand-centered luminescence. It is only slightly red shifted as compared to the ligand but partially quenched due to the strong π···π stacking interactions.

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Assembly of Three Cadmium(II) Complexes Based on Flexible α,ѡ-Bis(benzimidazolyl)alkane Ligands

Zeitschrift für Naturforschung B ◽

10.5560/znb.2012-0158 ◽

2012 ◽

Vol 67 (8) ◽

pp. 791-798 ◽

Cited By ~ 7

Author(s):

Jian-Chen Geng ◽

Cui-Huan Jiao ◽

Jin-Ming Hao ◽

Guang-Hua Cui

Keyword(s):

Solid State ◽

Chain Structure ◽

Helical Chain ◽

Supramolecular Network ◽

Stacking Interactions ◽

X Ray Diffraction ◽

X Ray ◽

Π Stacking ◽

Elemental Analyses ◽

Network Complex

Three flexible α,ѡ-bis(5,6-dimethylbenzimidazolyl)alkane ligands with different spacers were reacted with CdX2 (X = Cl, Br, I) hydrothermally, resulting in three coordination architectures, namely [CdI2(L1)]n (1), [CdBr2(L2)]n (2), and Cd2Cl4(L3)2 (3) [L1 = 1,3-bis(5,6- dimethylbenzimidazole)propane, L2 = 1,5-bis(5,6-dimethylbenzimidazole)pentane, L3 = 1,6- bis(5,6-dimethylbenzimidazole)hexane]. They have been characterized by elemental analyses, IR spectra, thermogravimetric (TG) analysis, and single-crystal X-ray diffraction. Complex 1displays a helical chain linked by the ligands L1, and a 2D supramolecular network is constructed through π-π stacking interactions; complex 2shows a helical chain structure with connections through two kinds of strong π-π stacking interactions into an intricate 3D supramolecular network; complex 3 contains dinuclear metallomacrocycles. The fluorescence properties of 1-3have been investigated in the solid state

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Synthesis, characterization and crystal structure of platinum(II) complexes with thiourea derivative ligands

European Journal of Chemistry ◽

10.5155/eurjchem.9.4.360-368.1774 ◽

2018 ◽

Vol 9 (4) ◽

pp. 360-368

Author(s):

Ebru Keskin ◽

Ummuhan Solmaz ◽

Gun Binzet ◽

Ilkay Gumus ◽

Hakan Arslan

Keyword(s):

Single Crystal ◽

Weak Interactions ◽

Platinum Complexes ◽

Stacking Interactions ◽

X Ray Diffraction ◽

Thiourea Derivatives ◽

X Ray ◽

Π Stacking ◽

Π Stacking Interaction ◽

In Cis

Thiourea derivatives [N-(di-n-propylcarbamothioyl)-4-fluorobenzamide (HL1) and N-(di-n-propylcarbamothioyl)-4-bromobenzamide (HL2)] and their platinum complexes have been successfully synthesized and structurally characterized by spectroscopic 1H NMR, 13C NMR, COSY, HMQC, and FT-IR techniques. The structure of both complexes was also confirmed by single crystal X-ray diffraction studies. The study of X-ray single crystal diffraction shows that the supramolecular aggregation of the complexes is stabilized via weak interactions as well as stacking interactions such as C-H···π and π···π. The cis-[Pt(L1-S,O)2 showed C–H···π and π···π stacking interactions, whereas only C–H···π stacking interaction was observed in cis-[Pt(L2-S,O)2]. In addition, the strong classical and non-classical intermolecular hydrogen bonds are not found in the prepared complexes. Therefore, it can be said that the C–H···π and π···π stacking interactions play an important role in the formation of supramolecular structures of the complexes.

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Synthesis and Structural Diversity of Triaryl(phenylethyl)silanes

Synthesis ◽

10.1055/s-0039-1690785 ◽

2020 ◽

Vol 52 (07) ◽

pp. 1025-1034 ◽

Cited By ~ 1

Author(s):

Marvin Linnemannstöns ◽

Beate Neumann ◽

Hans-Georg Stammler ◽

Norbert W. Mitzel

Keyword(s):

Ir Spectroscopy ◽

Single Crystal ◽

Diffraction Analysis ◽

Structural Diversity ◽

Stacking Interactions ◽

X Ray Diffraction ◽

X Ray ◽

Π Stacking ◽

Folded Structure ◽

Elemental Analyses

Starting from trichloro(phenylethyl)silane, six differently fluorinated triaryl(phenylethyl)silanes were synthesized by salt elimination reactions and their structures were determined by X-ray diffraction analysis. Tris(pentafluorophenyl)(phenylethyl)silane reveals a folded structure due to intramolecular π-stacking interactions, while those with a lower degree of fluorination show either intermolecular π-stacking or no interplay between the aryl groups. A similar folded structure was observed for (4-methylphenethyl)tris(pentafluorophenyl)silane and [2-(naphth-2-yl)ethyl]tris(pentafluorophenyl)silane, both generated from the corresponding trichlorosilanes. In contrast, the inversely fluorinated [2-(pentafluorophenyl)ethyl]triphenylsilane only revealed intermolecular π-stacking interactions. Compounds with tetrafluoropyridyl substituents behave differently; with these compounds, π-stacking is only observed between the fluorinated units. All compounds were analyzed by NMR and IR spectroscopy, elemental analyses and single-crystal X-ray diffraction, and found to have strong H/C/N/F···F and N···C contacts.

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Conformational analysis and potential anticancer activity of [Pt(phen)(L1-κS)2] studied by single crystal X-ray diffraction and variable temperature 1H and 195Pt NMR spectroscopy

New Journal of Chemistry ◽

10.1039/c8nj06010j ◽

2019 ◽

Vol 43 (9) ◽

pp. 3665-3672 ◽

Cited By ~ 2

Author(s):

Edmore F. Kangara ◽

Tebogo Peega ◽

Leonie Harmse ◽

Juanita L. van Wyk ◽

Demetrius C. Levendis ◽

...

Keyword(s):

Nmr Spectroscopy ◽

Conformational Analysis ◽

Single Crystal ◽

Anticancer Activity ◽

Variable Temperature ◽

Stacking Interactions ◽

X Ray Diffraction ◽

X Ray ◽

Π Stacking

Conformers of [Pt(phen)(L1-κS)2] observed in solution as a result of π-stacking interactions between the unusual κS-coordinated N,N-diethyl-N′-1-naphthoylthioureato ligands and 1,10-phenanthroline.

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Neue Pentaphosphaferrocene

Zeitschrift für Naturforschung B ◽

10.1515/znb-2009-0102 ◽

2009 ◽

Vol 64 (1) ◽

pp. 3-10 ◽

Cited By ~ 30

Author(s):

Fabian Dielmann ◽

Roger Merkle ◽

Sebastian Heinl ◽

Manfred Scheer

Keyword(s):

Crystal Lattice ◽

Stacking Interactions ◽

X Ray Diffraction ◽

X Ray ◽

Cyclopentadienyl Ligand ◽

Π Stacking ◽

Diffraction Structure ◽

Structure Determinations ◽

Phenyl Rings ◽

Derivatives Of

By cothermolysis of [CpRFe(CO)2]2 [CpR = η5-C5(CH2Ph)5 (Cpbn) (1) and η5-C5Me4C2H4SMe (CpS) (2)] with P4 phosphorus two novel pentaphosphaferrocenes of the formula [CpRFe(η5-P5)] [CpR = CpS (3), Cpbn (4)] have been synthesised and comprehensively characterised. These two products represent the first derivatives of this class of compounds with a functionalised as well as a sterically bulky adjacent cyclopentadienyl ligand. The pentabenzylcyclopentadienyl derivative 4 as well as both of the starting materials [CpRFe(CO)2]2 1 and 2 have been additionally characterised by X-ray diffraction structure determinations. The pentaphosphaferrocene 4 represents in the crystal lattice highly aggregated units via intra- and intermolecular π-stacking interactions of the phenyl rings of the Cpbn ligand.

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Synthesis, Topological Analysis and Properties of a Coordination Polymer with Butane-1,2,3,4-tetracarboxylato-bridged (Phenanthroline)cobalt(II) Units

Zeitschrift für Naturforschung B ◽

10.1515/znb-2011-0203 ◽

2011 ◽

Vol 66 (2) ◽

pp. 119-124 ◽

Cited By ~ 2

Author(s):

Hong-Lin Zhu ◽

Yue-Qing Zheng

Keyword(s):

Hydrothermal Reaction ◽

Magnetic Measurements ◽

Topological Analysis ◽

Magnetic Behavior ◽

Stacking Interactions ◽

X Ray Diffraction ◽

X Ray ◽

Π Stacking ◽

1D Chain ◽

A Chain

A hydrothermal reaction of Co(Ac)2 ・ 4H2O, butane-1,2,3,4-tetracarboxylic acid (H4BTC), 1,10-phenanthroline (phen) and NaOH carried out at 160 °C yielded a new complex [Co2(H2O)2(phen)2(BTC)]. The complex has been characterized by single-crystal X-ray diffraction, IR spectroscopy, TG-DTA analyses, elemental analyses, powder X-ray diffraction, and magnetic measurements. The Co ions are linked by BTC4− anions into a chain, and hydrogen bonding and π-π stacking interactions result in the formation of a 3D (3,4,6)-connected supramolecular architecture with the Schläfli symbol (43.62.8)2(46.66.83)(63)2. The temperature dependence of the magnetic susceptibility of the compound follows a Curie-Weiss law χm = C/(T −Θ) with C = 4.18(4) cm3 mol−1 K and Θ = −1.43(5) K, and the magnetic behavior can be interpreted by means of a 1D chain Fisher model, where the magnetic superexchange is transmitted via π ···π stacking interactions between adjacent phen ligands, and the best fit results in J = −0.05 cm−1, and zJʹ = 0.21 cm−1.

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