CrystEngComm Blog

Efficient conversion of solar energy to electricity is a dream we all share, in the natural world sunlight is the basis for nearly all life (excluding those deep see hydrothermal vents and chemo-autotrophic bacteria based communities!). If we could mimic this in our modern world, powering transport, industry and domestic environments with an environmentally friendly, abundant and free power source, we would surely be better off………….. but what’s the best way to do it?

SnO2 hollow nanospheres in DSSC's can give light-to-electricity conversion efficiencies of up to 6.02%

Dye sensitized solar cells (DSSC’s) have been an attractive prospect for some time now, they are relatively cheap and their light harvesting efficiency is dependent on dye absorption and charge separation. By designing hollow SnO₂ nanospheres enclosed with single crystalline nanoparticles, Jinghong Li and Lin Guo et al. have achieved a light-to-electricity conversion efficiency of 6.02%, which is among the highest in non-TiO₂ semiconductor oxides.

The nanostructure design means there is a very high surface area, allowing absorption of a great number of dye molecules, while the single crystalline structure has efficient charge separation properties. This design is proving to be a great candidate for future DSSC technologies…

SnO₂ hollow nanospheres enclosed by single crystalline nanoparticles for highly efficient dye-sensitized solar cells
Hua Wang, Bo Li, Jian Gao, Ming Tang, Hongbin Feng, Jinghong Li and Lin Guo

New synthesis route for metal fluorosulphates

Cathodes made from olivine-type LiFePO₄ are currently being investigated for use in batteries thanks to having properties such as high structural stability, low production costs and high theoretical capacities – but they are currently restricted by being unable to provide sufficient voltage.  A possible way to increase the voltage in such a system could be the isostructural replacement of (PO₄)^3- with (SO₄)^2- as well as the introduction of fluorine.

In their CrystEngComm Communication, Yongchun Zhu, Yitai Qian and colleagues have prepared the compound NaFeSO₄F in a single, short step (previous methods have taken more than 40 hours) using a benzene-water azeotrope, which is a mixture of liquids that boils at a constant temperature, maintaining the ratio of constituents. 
Could this method be adapted to synthesise other fluorosulphates in one step, such as LiZnSO₄F or NaZNSO₄F, for use as cathode materials?

Read the Communication to find out more – it’s currently free.

A novel benzene–water azeotrope route to new Na-based metal fluorosulphates NaFeSO₄F and NaFeSO₄F·2H₂O in one minute
Zhengqiu Yuan, Denghu Wei, Yan Wang, Yongchun Zhu, Yitai Qian and Kaibing Tang
CrystEngComm, 2012
DOI: 10.1039/C2CE25155H

Remember you can keep up to date with all the latest news in crystal engineering by liking us on facebook, following us on twitter or signing up to our e-alert service.

Carbaborane C-H groups are acidic and so are able to form hydrogen bonding interactions as donors. This can be exploited in the use of carbaboranes as coordinating anions that can be involved in agostic interactions with diverse metal centres. Agostic and electrostatic interactions for Ag···H-B are very rare.

In this advance article, Luís Cunha-Silva and Michaele Hardie report the synthesis and structural characterisation of two silver alkanedinitrile networks with cobalt carbaborane anions that have an exciting mix of short-range Ag···H interactions and geometries.

The complexes exhibit Ag centres that are purely coordinated by Ag···H-B interactions, which are highly uncommon coordination motifs. Both Ag···(H-B)₄ and Ag···(H-B)₆ centres were identified, and the cobalt carbaborane anions behaved as ligands through a mix of these agostic and electrostatic interactions.

This Hot Article is free to access for 4 weeks. You can keep up to date with the latest news in crystal engineering by liking us on facebook, following us on twitter or signing up to our e-alert service!

Linear halogen bond assembly

Lee Brammer and colleagues report crystal structures of halogen-bonded adducts between diiodoacetylene and nitrogen/oxygen acceptor groups showing the suitability of diiodoacetylene as a ditopic connector. 

The strength in the halogen bond is due to the electron-withdrawing effect from the sp-hybridised carbon atom in diiodoacetyle.  Being able to form such strong intermolecular interactions via such a small linear molecule with two conformationally constrained faces makes diiodoacetylene a useful building block in crystal engineering and supramolecular chemistry.

Read the paper for free…

Diiodoacetylene: compact, strong ditopic halogen bond donor
Catherine Perkins,  Stefano Libri,  Harry Adams and Lee Brammer
CrystEngComm, 2012
DOI: 10.1039/C2CE00029F

Here is a selection of other recent work from Lee Brammer and colleagues…

Different structural destinations: comparing reactions of [CuBr2(3-Brpy)2] crystals with HBr and HCl gas
Guillermo Mínguez Espallargas, Alastair J. Florence, Jacco van de Streek and Lee Brammer
CrystEngComm, 2011, 13, 4400-4404
DOI: 10.1039/C1CE05222E
From themed issue Dynamic behaviour and reactivity in crystalline solids

Synthesis and polymorphism of (4-ClpyH)2[CuCl4]: solid–gas and solid–solid reactions
Iñigo J. Vitorica-Yrezabal, Rachel A. Sullivan, Stephen L. Purver, Caroline Curfs, Chiu C. Tang and Lee Brammer
CrystEngComm, 2011, 13, 3189-3196
DOI: 10.1039/C0CE00628A
From themed issue Reactions in molecular solids and host–guest systems

Effects of halogen bonding in ferromagnetic chains based on Co(II) coordination polymers
Juan M. Clemente-Juan, Eugenio Coronado, Guillermo Mínguez Espallargas, Harry Adams and Lee Brammer
CrystEngComm, 2010, 12, 2339-2342
DOI: 10.1039/C003078C
From themed issue New Talent