Dalton Transactions Blog

Oelkers and Sundermeyer, in this HOT Article, present a general approach towards 1,4-diazabutadiene (DAD^S) ligands with various onium cations via acid–base reactions and towards their noble-metal complexes. The solubility and immobilization of such complexes in ILs is quantitatively shown via photometric measurements using a chromophoric Mo(0) DAD^S complex in a toluene/[BMIM]OTf biphasic mixture as a model system. It was shown that complexes with ionic liquid (IL) – typical onium salts of sulfonated diazadienes as ligands are strongly retained in an IL phase in contact with a toluene phase, which may make these ligands potentially useful in IL/organic biphasic catalysis.

Read more for FREE until mid-November:

Sulfonate-tagged 1,4-diazabutadiene (DAD^S) ligands and their noble-metal complexes – synthesis, characterization and immobilization in ionic liquids
Benjamin Oelkers and Jörg Sundermeyer
Dalton Trans., 2011, Advance Article
DOI: 10.1039/C1DT10939A

In this HOT Article, US researchers have presented an in depth reactivity study of alkynylgold species and phosphonates. As protodeauration is the main terminating step in gold catalysis, the effect of labile P–H bonds will be of interest to those studying gold catalysis, as well as those studying phosphite chemistry.

Read more about these gold complexes for FREE until mid-November at:

P–H activation using alkynylgold substrates: steric and electronic effects

Gerald F. Manbeck, Mark C. Kohler, Meghan R. Porter and Robert A. Stockland Jr.
Dalton Trans., 2011, Advance Article
DOI: 10.1039/C1DT11337B

Mike George, Paul Raithby and co-workers using photocrystallography to identify isomers in a nickel complex. Photocrystallography allows the groups to study metastable linkage isomers and they have shown that the technique provides scope for the identification of new species.

Photocrystallography involves the photo-activation of species within a crystalline lattice. It brings a dynamic aspect to X-ray crystallographic experiments, so that reactions within a crystal can be monitored as they occur or the structures of molecules in metastable or short-lived photo-activated states can be determined. Read more about the group’s findings in their Dalton Transactions Hot Article:

Photocrystallographic identification of metastable nitrito linkage isomers in a series of nickel(II) complexes
Simon K. Brayshaw, Timothy L. Easun, Michael W. George, Alexandra M. E. Griffin, Andrew L. Johnson, Paul R. Raithby, Teresa L. Savarese, Stefanie Schiffers, John E. Warren, Mark R. Warren and Simon J. Teat
Dalton Trans., 2011, DOI: 10.1039/C1DT11379H

Phalguni Chaudhuri and colleagues, from the Max-Planck-Institut in Mulheim, Germany, investigate the interactions between a potentially tetradentate tripodal ligand and the biologically important metal, Vanadium. What were the resulting complexes? Find out in  their Hot Article – FREE to read until mid November.

Non-oxo 5-coordinate and 6-coordinate vanadium(IV) complexes with their precursor [LVIII(CH3OH)]0, where L = a trianionic aminetris(phenolate)-[N,O,O,O] donor ligand: a magnetostructural and EPR study
Takashi Kajiwara, Rita Wagner, Eckhard Bill, Thomas Weyhermüller and Phalguni Chaudhuri
Dalton Trans., 2011, DOI: 10.1039/C1DT11277E

In their Dalton Trans. Hot Article, a group of Japanese chemists led by Hisako Sato, used vibrational circular dichroism (VCD) spectroscopy to study the stereochemical properties of a star-burst type tetranuclear Ru(III) complex. By comparing the VCD spectra of eight diastereomeric enantiomers, they were able to see the homo- or hetero-chiral nature of the bridging part of the compound which connected the central core and the peripheral region

Chirality effects on core-periphery connection in a star-burst type tetranuclear Ru(III) complex: application of vibrational circular dichroism spectroscopy
Hisako Sato, Fumi Sato, Masahiro Taniguchi and Akihiko Yamagishi
Dalton Trans., 2012, Advance Article
DOI: 10.1039/C1DT11510C

This HOT article by Mukherjee et al. reports the synthesis, structure, magnetic properties and DFT studies of four Cu(II)-azide polymers. Cu(II)-azide polymers are presently  being studied by many groups due to their interesting structural variation and magnetic properties. In this paper, three out of the four compounds studied are of new structural topologies.  All four complexes exhibit an overall ferromagnetic behaviour; the magnetic results are corroborated by DFT studies. The structural analysis shows how a simple change in the structure of the blocking ligand can generate entirely different structures and magnetic properties, even though the basic structures seems to be almost identical. It is also shown that another blocking diamine does not produce similar complexes under the same reaction conditions, which leads to the question: are certain compositions forbidden?

Read more about forbidden compositions and magnetic behaviour for FREE until the 2nd November at:
Cu^II-azide polymers with various molar equivalents of blocking diamine ligands: synthesis, structures, magnetic properties with DFT studies
Sandip Mukherjee, Yogesh P. Patil and Partha Sarathi Mukherjee
Dalton Trans., 2011, Advance Article
DOI: 10.1039/C1DT11312G

Frank Neese (Max Planck) and Serena DeBeer (Cornell University), predict iron K-edge XAS pre-edge features for iron complexes using time-dependent density functional theory in this Dalton Transactions Hot article.

This work is building on the teams earlier investigations into ferrous and ferric complexes. The group will use their improved understanding of high valent iron intermediates to explain more about the behaviour of metalloproteins, and in this case they look at the heme active site of P450.

This paper is part of a themed issue guest edited by Stuart MacGregor (Heriot-Watt) on Computational Chemistry of Molecular Inorganic Systems that will be published online in the next few weeks. Make sure you hear about it by signing up to the Dalton Transactions table of contents e-alerts.

Read the full article for FREE  until 8th November to find out more about the use of X-ray absorption spectroscopy to understand metalloproteins…

Prediction of high-valent iron K-edge absorption spectra by time-dependent Density Functional Theory
P. Chandrasekaran, S. Chantal E. Stieber, Terrence J. Collins, Lawrence Que, Jr., Frank Neese and Serena DeBeer
Dalton Trans., 2011, DOI: 10.1039/C1DT11331C

In this HOT article, Constantinos J. Milios and co-workers describe the synthesis, crystal structures and magnetic properties of (a hexanuclear and an octanuclear) manganese(III) complexes based on a new oxime ligand, 2-dihydroxy-2-phenylacetamidine.  This is the first time that this ligand has been  used for the synthesis of polynuclear complexes of any transition metal ion. Even though the hexanuclear complex resembles the previously reported [Mn₆] clusters with salicyl-based oximes, the octanuclear complex presents a new structural type in Mn chemistry. Both complexes display moderate spin ground states (S = 3). The authors believe this new ligand is a promising candidate for a new extended family of manganese complexes with interesting magnetic properties and as impressive structures as its parent salicyl- or pyridyl-based oxime ligands.

Read more about this new ligand and potential magnetic properties for FREE until 25 th October at:

A new oxime ligand in manganese chemistry: a [Mn₈] and a [Mn₆] cage from the use of 2-dihydroxy-2-phenylacetamidine
Andreas G. Flamourakis, Demetrios Tzimopoulos, Milosz Siczek, Tadeusz Lis, James R. O’Brien, Pericles D. Akrivos and Constantinos J. Milios
Dalton Trans., 2011, Advance Article
DOI: 10.1039/C1DT11455G

Peter Sadler from Warwick University, and collaborators at the Chinese Academy of Sciences have developed a ruthenium arene anticancer complex that inhibits the action of protein tyrosine phosphatase 1B, which regulates insulin levels.

In this Dalton Transactions Hot article the team investigate how the complex interacts with the active site of PTP1B by using a similiar shaped molecule as a model. Their compound was found to have an IC₅₀ of 19 μM.

Read the full article for FREE until 2nd November to find out more about how this anticancer compound works…

Reactions of an organoruthenium anticancer complex with 2-mercaptobenzanilide—a model for the active-site cysteine of protein tyrosine phosphatase 1B
Yumiao Han, Qun Luo, Xiang Hao, Xianchan Li, Fuyi Wang, Wenbing Hu, Kui Wu, Shuang Lü and Peter J. Sadler
Dalton Trans., 2011, DOI: 10.1039/C1DT11189B

Keep up to date with the latest news and research in inorganic chemistry: sign up to the Dalton Transactions e-alert, check out our blog, and follow us on Twitter.