Thermal and odd–even behaviour in a homologous series of lithium n-alkanoates

Odd–even chain packing, molecular and thermal models for some long chain sodium(I) n-alkanoates

“…Such observations are similar to those reported for zinc(II) n-alkanoates [1,26]; hence, similar inter-chain van der Waals interactions are indicated. Furthermore, similar C1 chemical shifts were reported by Ellis [27] and Chida [20], for lithium(I) n-alkanoates (C1 $ 185 ppm), indicating similar metal-carboxylate coordination. Interestingly, odd-even alternation is observed in the C2 resonances (Fig.…”

“…Similarities in the density data, 13 C NMR, infrared and powder XRD patterns, confirm that the head group structures for these compounds are similar to those reported by Chida [20], for some short chain lithium(I) n-alkanoates, adduced from single crystal diffraction and Ellis [37], for several long chain adducts, based on X-ray powder diffraction. Hence, it is proposed that, for the compounds reported in this study, the carboxyl moieties are coordinated in a chelating bidentate mode to metal centers occupying tetrahedral holes due to extensive head group intermolecular interactions (Scheme 2).…”

Thermal decomposition of barium valerate in argon

“…4) appears in the DTA trace. It reminds of the oscillations observed upon heating Cu-dodecanoate [30] and some 8 Li alkanoates [31]. In the temperature interval situated between this oscillation and the onset of DTA peak III, the XRD patterns show the appearance and growth of a new broad reflection at 2θ = 3.8° and the collapse of the reflections present at lower temperatures (Fig.…”

Theories and experimental investigations of the structural and thermotropic mesomorphic phase behaviors of metal carboxylates

“…For example, according to Binnemans [79], five pre-melting transitions at 376, 387, 400, 447 and 484 K (mesophase) followed by the melt at 508 K were observed for silver(I) n-dodecanoate. However, investigations by Nelson [70] showed that the phase sequence for this compound was composed of three pre-melting transitions at 374, 388 and 485 K followed by the melt at 510 K. Similar discrepancies were observed in the DH and DS values as well as the number of transitions in the phase sequences for the other homologues [70,76]. Decomposition of these compounds at the melt was well documented; [20] hence, several proposals for their decomposition products and mechanism have been reported.…”

“…However, this study was limited since there was no description of the metal carboxylate coordination, type of molecular packing and/or the effect of chain length on their lattice structures. Recently, more extensive structural studies were carried out by White et al [76] and it was concluded, based on room temperature PXRD and IR data, that the ionic molecules were packed as lamellar bilayer structures in a triclinic crystal system composed of fully extended all-trans hydrocarbon chains. Interestingly, single crystal structures reported by Casado et al [77] for lithium(I) propanoate and pentanoate showed carboxylate groups bound in a chelating bidentate mode to tetrahedral lithium(I) ions.…”