CrystEngComm Blog

Designing metal–organic frameworks (MOFs) with structure-based properties has received a considerable amount of interest in recent years. This is due to their fascinating molecular structures and potential applications in molecular adsorption, separation, heterogeneous catalysis, magnetism and electrical conductivity.

The basic strategy for constructing MOFs is to use an appropriate organic ligand, especially bridging ligands containing multi-dentate oxygen or nitrogen donors, to coordinate to the metal centers.  Cucurbit[n]uril (n = 5–8, 10, abbreviated as Q[n]) is a class of barrel-shaped organic macrocyclic ligand with identical carbonyl-laced portals on each side. The polar carbonyl groups of the Q[n]s are capable of metal-coordination and therefore Q[n]s are promising building blocks for the construction of coordination polymers.

Now in this CrystEngComm Hot Article, Zhu Tao et al., report the synthesis and crystal structures of three coordination polymers with K⁺, Rb⁺ and Cs⁺ coupled with (HO)₁₀Q[5] as the building block.

Read this article for free until 5th May 2011 here.

Coordination polymers constructed from alkali metal ions and (HO)10cucurbit[5]uril
Xin Xiao, Zhu Tao, Sai-Feng Xue, Yun-Qian Zhang, Qian-Jiang Zhu, Jing-Xin Liu and Gang Wei
CrystEngComm, 2011, Advance Article, DOI: 10.1039/C1CE05162H

In this CrystEngComm Hot Article, which is part of a themed issue celebrating the achievements of the late Professor Fumio Toda entitled “Reactions in Molecular Solids and Host-Guest Systems“, Anthony Coleman and Oksana Danylyuk et al. report their results on a systematic investigation of the solid-state complexes of para-sulphonato calix[4]arene (C4S) with 1,10-phenanthroline (Phen).  The team prepared four supramolecular complexes of C4S with Phen in single-crystal form and their structures determined by X-ray diffraction.

Cyclodextrins, crown ethers, cryptands and calix[n]arenes are the most important categories of supramolecular hosts. Acid derivatives such as para-sulphonato-, O-phosphonato- or O-alkylcarboxylato-calix[n]arenes present the advantage of being hydrosoluble and thus apt for study with regard to their biological properties and their complexation abilities towards molecules of biological interest.

Read the article for free until 29th April 2011 here.

Supramolecular versatility in the solid-state complexes of para-sulphonatocalix[4]arene with phenanthroline
Barbara Lesniewska, Oksana Danylyuk, Kinga Suwinska, Tomasz Wojciechowski and Anthony W. Coleman
CrystEngComm, 2011, Advance Article, DOI:10.1039/C0CE00515K

In this Perspective article, Gerd Kaupp, from the University of Oldenburg, Germany looks at the varied use of milling with metals according to reaction types.

This is an essential guide to mechanical milling, where Kaupp covers the bredth of the field from alloying, brittle milling and ductile kneading, to milling of metals with infinitely covalent non-metals, with metal salts and hydrides, molecular crystals and carbon, with gases, and with organic halides and ketones, as well as with other metals.

Kaupp particularly emphasises that in many cases it is easy to reduce the long milling times found in a great deal of the literature  ‘based on the chemical and technical understanding of the various processes’.

Read the full article to find out more about ways to improve your milling…

Reactive milling with metals for environmentally benign sustainable production
G. Kaupp
CrystEngComm, 2011, Advance Article
DOI: 10.1039/C1CE05085K, Highlight

In this CrystEngComm Hot Article, Angelo Gavezzotti from the University of Milan has developed a new algorithm to simulate the processes that lead from an isotropic liquid to a crystal structure.

The procedure was applied to the transformation of n-hexane from a liquid to a solid and the structure generated was very similar to the real crystal structure.

It is currently very difficult to experimentally monitor the early stages of molecular recognition and aggregation in a liquid that lead to the nucleation of crystals of organic molecules.

This simulation will provide new insight into the process of molecular crystallization.

Read more for FREE until Thursday 21st April 2011.

Can a computer crystallize a liquid? Molecular simulation of continuous trajectories from liquid to crystalline n-hexane
Angelo Gavezzotti
CrystEngComm, 2011, Advance Article
DOI: 10.1039/C1CE05106G, Paper

In this CrystEngComm Hot Article, Zhang et al. synthesised Si-doped In₂O₃(ZnO)₃ (SDIZO) nanobelts using chemical vapour deposition (CVD).  The Si behaves as a suitable n-type dopant that gives stable n-type conductivity with high electron concentration and low resistivity.  The electron transport properties of the nanobelt devices show a non-linear characteristic due to the existence of the intrinsic statistical potential distribution.

Transparent oxide semiconductor (TOS) thin films with high optical transparency and good controllability of carrier generation have been studied intensively for photonic and electronic devices, such as, short-wavelength light emitting diodes and transparent field-effect transistors (TFETs).

Read this article for free until 20th April 2011 here.

Synthesis and transport properties of Si-doped In₂O₃(ZnO)₃ superlattice nanobelts
J. Y. Zhang, Y. Lang, Z. Q. Chu, X. Liu, L. L. Wu and X. T. Zhang
CrystEngComm, 2011, Advance Article, DOI: 10.1039/C1CE00004G

This CrystEngComm Hot article describes the “liquid-assisted” solid-state synthesis of ruthenium^III/cobalt^III-Hbiim complexes.

The authors use a mechanochemical route and investigate the crystallisation mechanism.

They were particularly surprised to discover that ‘the phase obtained from the solid-state reaction may be different from that prepared from solution in some cases, even though they crystallize from an identical solution.’

Read the full paper to find out more about the surprising phase change observed…

Liquid-assisted solid-state reaction: assembly of (6,3) and (10,3) hydrogen-bonded networks based on [M(Hbiim)3] by oxidation of [M(H2biim)3]2+ complexes in the presence of acetate anions
Yu-Hui Tan, Li-Fei Yang, Man-Li Cao, Jin-Ji Wu and Bao-Hui Ye
CrystEngComm, 2011, Advance Article
DOI: 10.1039/C1CE00009H, Paper

READ FOR FREE until 16th April

In this CrystEngComm Hot Article, Cao, Okada et al. describe a simple but effective catalyst-tailored chemical vapour deposition method for growing ZnO nanowires and nanobelts in a controlled way.  The ZnO nanobelts grown without using any catalyst or dopant show different optical properties than nanowires grown with a gold-catalyst assisted vapour-solid-liquid process.

Nanobelts and nanowires are the most important candidates for potential optoelectronic applications. When compared with nanowires, there is no common growth strategy that can be applied for nanobelts and, therefore, growth of ZnO nanobelts is more difficult.

Read more about these fascinating structures for free until 12th April 2011, here.

Catalyst/dopant-free growth of ZnO nanobelts with different optical properties from nanowires grown via a catalyst assisted method
B. Q. Cao, Z. M. Liu, H. Y. Xu, H. B. Gong, D. Nakamura, K. Sakai, M. Higashihata and T. Okada
CrystEngComm, 2011, Advance Article, DOI: 10.1039/C1CE05058C

In this CrystEngComm Hot Article, Chinese scientists have prepared complex indium- and gallium-doped zinc oxide nanostructures with twin boundaries.

Three-edged nanobelts and hexagonal-disk strings were fabricated using a thermal evaporation method. Despite their differences in morphology they have the same twin boundaries, which the authors explain by introducing a twin core.

Understanding the growth of these nanostructures opens up the potential for assembling nanoscale building blocks into sophisticated structures.

Read more for FREE until 12th April 2011
Group III element-doped ZnO twinning nanostructures
L. L. Wu, F. W. Liu and X. T. Zhang
CrystEngComm, 2011, Advance Article
DOI: 10.1039/C1CE05088E, Paper

Zhien Lin and collegues from Sichuan University, China have developed a promising open-framework beryllium phosphite in this CrystEngComm Hot article.

The team made (C₂H₈N)₂[Be₃(HPO₃)₄], referred to as BeHPO-1, which was found to have a low density, integrating large 16-ring channels, and an interrupted 3,4-connected framework, and has potential for use in catalysis, separation, and ion-exchange processes.

BeHPO3-1 has a very low-density framework, which is better than other open-framework metal phosphates, and similiar to mesoporous germanate SU-M.

The authors were particularly excited to discover both left- and right-handed helical channels in the structure and hope that this material will be ‘a step forward toward the rational construction of new open-framework inorganic solids with low densities’

Read the full article to find out more about this beryllium-containing open framework…

(C2H8N)2[Be3(HPO3)4]: a low-density beryllium phosphite with large 16-membered rings and helical channels
Xiuchao Luo, Daibing Luo, Maochu Gong, Yaoqiang Chen and Zhien Lin
CrystEngComm, 2011, Advance Article
DOI: 10.1039/C1CE05117B, Communication

FREE TO READ until 4th April

This CrystEngComm Hot article details the preparation of a new pentanuclear heterotrimetallic complex [Cu₂CoNi₂(Me₂Ea)₆Cl₄] with an unusual heterotrimetallic structure, like that of a butterfly.

This work is part of the authors investigation into the coordination chemistry of  complexes containg copper, cobalt and nickel.

Read the full article to find out more about the ‘butterfly-like’ structure…

Direct synthesis and crystal structure of a new pentanuclear heterotrimetallic Cu/Co/Ni complex with 2-(dimethylamino)ethanol. Discussion of possible “butterfly-like” molecular structure types
Dmytro S. Nesterov, Claudia Graiff, Antonio Tiripicchio and Armando J. L. Pombeiro
CrystEngComm, 2011, Advance Article
DOI: 10.1039/C1CE05049D, Paper

FREE TO READ until 8th April