The articles published in the tenth anniversary issue of CrystEngComm are reviewed. The issue highlighted the state-of-the-art of crystal engineering and new trends and developing areas in crystal engineering. In particular, the following article emphasises developments in the areas of intermolecular interactions, notably hydrogen and halogen bonds; metal–organic frameworks or coordination polymers; polymorphism and solvates.

Recent advances in crystal engineering

By controlling the pH value of the reaction system, two sets of lanthanide (Ln)–tris((4-carboxyl)phenylduryl)amine (Ln = Ce, Pr, Nd, Sm) frameworks have been generated. Four isostructural noninterpenetrating frameworks (FIR-8 to FIR-11) are constructed from rod-shaped secondary building units and four other isostructural frameworks (FIR-12 to FIR-15) based on single Ln nodes are described as 8-fold interpenetrating dia-type nets. Gas sorption measurements for FIR-8 give a Langmuir surface area of 633.8 m2·g–1 and a H2 uptake of 165.2 cm3·g–1 at 77 K and 1 atm. However, FIR-12 with smaller pores can hardly adsorb any N2 and H2. Because both FIR-8 and FIR-12 crystallize in acentric space group, the second-harmonic generation (SHG) measurements indicate that both of them display strong powder SHG efficiencies, which are approximately 8 and 3 times as strong as that of a potassium dihydrogen phosphate powder. In addition, the fluorescent emissions of all compounds in the solid state are also investigated in d...

Gas sorption, second-order nonlinear optics, and luminescence properties of a series of lanthanide-organic frameworks based on nanosized tris((4-carboxyl)phenylduryl)amine ligand.

The syntheses, structures and thermal properties of three coordination networks [Zn(L11)(1,4-BDC)]·H2O (L11 = N,N′-di(4-pyridyl)adipoamide; 1,4-H2BDC = 1,4-benzenedicarboxylic acid), 1, [Cd(L11)(1,4-BDC)]·2H2O, 2, and [Zn2(L22)(1,4-BDC)2]·2CH3OH (L22 = N,N′-di(4-pyridyl)dodecanamide), 3, are reported. Complexes 1 and 2 show the dia topology with the rare 8- and 9-fold interpenetrating modes, respectively, while 3 exhibits an interpenetrating 3-fold framework with the pcuZn2(COO)2 dimer decorated topology. Complex 2 shows the maximum number of interpenetration presently known for interpenetrating diamondoid networks of coordination networks containing mixed spacer ligands.

Highly interpenetrated diamondoid nets of Zn(II) and Cd(II) coordination networks from mixed ligands

A series of seven divalent coordination polymers based on 5-iodo-isophthalic acid (5-iipa) and ancillary nitrogen ligands (phen = 1,10-phenanthroline, bpe = 1,2-bis(4-pyridyl)ethene, p-bix = 1,4-bis(imidazol-1-ylmethyl)-benzene, m-bix = 1,3-bis(imidazol-1-ylmethyl)-benzene), namely, [Zn2(5-iipa)2(phen)2(H2O)]n (1), [Zn(5-iipa)(bpe)1.5]n (2), [Cd2(5-iipa)2(phen)2]n (3), [Mn2(5-iipa)2(phen)2]n (4), [Mn4(5-iipa)4(bpe)4·5H2O]n (5), [Co(5-iipa)(p-bix)]n (6), and [Co(5-iipa)(m-bix)]n (7), have been synthesized. The structure of compound 1 exhibits a double zigzag metal–organic chain, and such chains are further united together to generate a three-dimensional (3D) supramolecular structure through interchain I···π interactions. Compound 2 features interesting 3-fold parallel interpenetrated two-dimensional (2D) → 3D network motifs which are stabilized by interlayer I···π, π···π, and C–H···π interactions. In isomorphous compounds 3 and 4, the 5-iipa2– ligand acts as a μ3-bridge to connect metal atoms to form a 2D ...

http://or.nsfc.gov.cn/bitstream/00001903-5/20607/1/1000002148765.pdf

Halogen Bonding in the Assembly of Coordination Polymers Based on 5-Iodo-Isophthalic Acid

Four metal–organic coordination compounds Zn2(bcbp)Cl4 (1), Zn(bcbp)(PO3F) (2), [CdCl(Hbcbp)(bcbp)]·(ClO4)2 (3), and [Cd2(bcbp)4]·(ClO4)·F3 (4) (H2bcbp·2PF6 = 1,1′-bis(4-carboxyphenyl)-(4,4′-bipyridinium) hexafluorophosphate) have been synthesized via a solvothermal method and structurally characterized. Compound 1 is a 1D coordination polymer, while compound 2 shows a 2D + 2D → 3D inclined polycatenation structure. In the case of compound 3, due to the capped chlorine atoms and uncoordinated carboxyl of bcbp ligand, it exhibits a 1D T-shaped coordination configuration. Compound 4 is an unprecedented 13-fold interpenetrating structure with huge diamondoid frameworks. Because of the presence of electron-deficient bipyridinium moieties, the photochromic behaviors of these compounds have also been studied. Interestingly, only compounds 1–3 exhibit color changes under light irradiation. The impact of these anions on the photochromic process is discussed.

Anion-Mediated Architecture and Photochromism of Rigid Bipyridinium-Based Coordination Polymers

The modular self-assembly of methanetetrabenzoic acid with similar linear linkers, phenazine and 4,4'-bipyridine, affords two different interpenetrating diamondoid frameworks which show a normal 7-fold mode of interpenetration (class Ia), and an unusual 18-fold interpenetration (class IIIb, [3 x 3 x 2]), respectively.

Organic hydrogen-bonded interpenetrating diamondoid frameworks from modular self-assembly of methanetetrabenzoic acid with linkers

Zigzag bipyridine (azpy, bipy-ete) induced crystalline assembly of the tetrahedral module methanetetrabenzoic acid to form the novel hydrogen-bonded organic framework with an unusual 3-fold interpenetrated pcu (α-polonium) topology.

Zhi-Tang Huang

Papers

Organic hydrogen-bonded interpenetrating diamondoid frameworks from modular self-assembly of methanetetrabenzoic acid with linkers

Construction of 3-fold interpenetrated pcu organic frameworks from methanetetrabenzoic acid with zigzag bipyridines