Recurrent H-bond graph motifs between metal tris-ethylenediamine cations and uncoordinated oxalate anions: Fitting a three pin plug into a two pin socket

Abstract

Conflict of symmetry favours unconventional hydrogen bonding: Bifurcated interactions occur between a 3-fold symmetric H-bond donor and a 2-fold symmetric H-bond. R graphs and a tendency to form bifurcated hydrogen bonds. The oxalate geometric parameters of twist and C-C bond length in our compounds are correlated with data from related structures in the CSD.

Beyond the Simple Copper(II) Coordination Chemistry with Quinaldinate and Secondary Amines

“…The amine-to-copper(II) bond lengths in our compounds are rather similar. In a series of piperidine complexes, the one in a five-coordinate [Cu(quin) 2 (pipe)] (6) is slightly shorter than the ones in the [69][70][71][72]. The morphlycarbamate, the counter-anion of 5, is in a chair conformation (Figure 9).…”

“…Five rings are in the usual chair conformation, whereas one, the internal N1 ring, is in the boat conformation. The dimensions of the heteronuclear rings were compared to dimensions [69][70][71][72]. The morphlycarbamate, the counter-anion of 5, is in a chair conformation (Figure 9).…”

An X-ray investigation of stereoselectivity in the interactions of [Co(en)3]3+with [Co(ox)3]3−(en is ethane-1,2-diamine and ox is oxalate)

“…Metal-metal distances are much longer, in the range 7.009-7.564 A ˚. This latter type of interaction is also commonly seen with uncoordinated oxalate (Keene et al, 2012).…”

“…Usefully, Keene and co-workers (Keene et al, 2012) have examined the hydrogen-bond networks in oxalate-containing salts of [Co(en) 3 ] 3+ and related species, and have identified a number of interactions for comparison with those involving metal-containing oxalate anions. In this article, the structure of the racemic salt [Co(en) 3 ][Co(ox) 3 ]Á5H 2 O, (I) (Scheme 1), is reported and the structure discussed.…”

Hydrogen-bonding chain and dimer motifs in pyridinium and morpholinium hydrogen oxalate salts

“…Our research group has an interest in these precursors as part of our investigations into molecular magnets (Keene, et al 2010), not only for their usefulness in this role, but for the complex hydrogen-bonded structures that often arise on crystallization. Previous work from our group has focused on the structure of discrete oxalate dianions and drawn correlations between torsion angles, bond lengths and the crystal packing (Keene et al, 2012).…”