N-Alkyl pyrrolidone ether podands as versatile alkali metal ion chelants

Abstract

'N-alkyl pyrrolidone ether podands as versatile alkali metal ion chelants.', Dalton transactions., 43 (8). pp. 3153-3161.Further information on publisher's website:Publisher's copyright statement:Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details.

Stable Borane Adducts of Alcoholates and Carboxylates

“…The sodium cation in 1 and 2 is chelated by 15‐crown‐5 and coordinates to the O1 connected to the boron atom [Na1–O1 = 2.439(3) ( 1 ) and 2.408(2) Å ( 2 ), respectively], which are significantly longer than in NaOMe [Na–O = 2.32(1) Å, determined by X‐ray powder diffraction] . In dimeric [Na 2 (μ‐{2‐[2‐(2‐oxo‐pyrrolid‐1‐yl)‐ethoxy]‐ethyl}‐pyrrolid‐2‐one) 2 (MeOH) 2 ](PF 6 ) 2 the interatomic Na–O distance of 2.329(3) Å is significantly shorter than in 1 and 2 . The C1–O1 distance of 1.423(4) ( 1 ) and 1.432(3) ( 2 ) Å] is slightly elongated with respect to methanol coordinating in [Na 2 (μ‐1) 2 (MeOH) 2 ](PF 6 ) 2 [1.398(4) Å] and in the range of NaOMe [C–O 1.41(4) Å] .…”

Modulating the hydration behaviour of calcium chloride by lactam complexation

“…This structure is in contrast to the alkali metal complexes of L1 in which the ether oxygen atoms chelate the metal centres. 7 The pentagonal bipyramidal Ca(1) ion binds two oxygen atoms from ligand molecules in addition to five bound water molecules, giving an overall coordination number of seven. The geometry at the metal centre is slightly distorted in the axial direction with a O(1)-Ca(1)-O(6) angle of 171.98 (7) o .…”

“…The high polarity of the lactam amide carbonyl functionality enables complexation of a range of oxophilic metal ions such as alkali metals. 7 Englert and coworkers have analysed the calcium chloride complexes reported in the Cambridge Structural Database (CSD) and found a high proportion of Ca-O contacts in 6-coordinate complexes, and therein provided additional support for the oxophilic nature of the metal centre. 8 Reports of calcium coordination complexes with DMF 9 and N-methylacetamide 10,11 ligands provide support for the suitability of amide containing ligands for complexation and stabilisation of calcium chloride.…”

Boric acid co-crystals in guar gelation

“…This shift is similar to those seen upon hydration and metal complexation of 1 and is indicative of a shift to the enolate resonance form and hence strong hydrogen bonding interactions. 33,34 The co-crystal was also prepared mechanochemically. 35 Solvent-free grinding of 1 and boric acid, in a 1:2 ratio using a pestle and mortar, results in the immediate formation of a white paste that transforms to a white crystalline solid upon air drying over a period of 3 hours at room temperature.…”