N7-(carboxymethyl)guanine-lithium crystalline complex: a bioinspired solid electrolyte

Electrochemical device with components having direct significance to biological life processes is a potent futuristic strategy for the realization of all-round green and sustainable development. We present here synthesis design, structural analysis and ion transport of a novel solid organic electrolyte (G7Li), a compound reminiscent of ion channels, derived from regioisomeric N7-guanine-carboxylate conjugate and Li-ions. G7Li, with it's in-built supply of Li(+)-ions, exhibited remarkably high lithium-ion transference number (= 0.75) and tunable room temperature ionic conductivity spanning three decades (≈10(-7) to 10(-3) Ω(-1) cm(-1)) as a function of moisture content. The ionic conductivity show a distinct reversible transition around 80-100 °C, from a dual Li(+) and H(+) (<100 °C) to a pure Li(+) conductor (>100 °C). Systematic studies reveal a transition from water-assisted Li-ion transport to Li hopping-like mechanism involving guanine-Li coordination. While as-synthesized G7Li has potential in humidity sensors, the anhydrous G7Li is attractive for rechargeable batteries.

Ionic conductivity studies of polymeric electrolytes containing lithium salt with plasticizer

New plasticized polymer electrolytes were synthesized based on poly ethylene oxide (PEO), Poly (N,N-dimethylamino-ethyl-methacrylate) (PDMAEMA), LiN(CF₃SO₂)₂ (LITFSI) as the salt and tetraethylene glycol dimethyl ether(tetraglyme) and EC + PC as plasticizers. The preparation and characterization of the polymer electrolytes were investigated as a function of temperature and various concentrations of LITFSI. Impedance spectroscopy and differential scanning calorimeter (DSC) were used to characterize the effects of various temperature, lithium salt concentration and two plasticizers on conductivity. The complex of PDMAEMA/PEO/LiTFSI/tetraglyme (S2) exhibits higher conductivity (4.74 × 10⁻⁴ S cm⁻¹at 25 °C) than PDMAEMA/PEO/LiTFSI/EC + PC (S1).

The science and practice of lithium therapy

Introduction: Despite more that 60 years of clinical experience, the effective use of lithium for the treatment of mood disorder, in particular bipolarity, is in danger of becoming obsolete. In part, this is because of exaggerated fears surrounding lithium toxicity, acute and long-term tolerability and the encumbrance of life-long plasma monitoring. Recent research has once again positioned lithium centre stage and amplified the importance of understanding its science and how this translates to clinical practice.

Objective: The aim of this paper is to provide a sound knowledge base as regards the science and practice of lithium therapy.

Method: A comprehensive literature search using electronic databases was conducted along with a detailed review of articles known to the authors pertaining to the use of lithium. Studies were limited to English publications and those dealing with the management of psychiatric disorders in humans. The literature was synthesized and organized according to relevance to clinical practice and understanding.

Results: Lithium has simple pharmacokinetics that require regular dosing and monitoring. Its mechanisms of action are complex and its effects are multi-faceted, extending beyond mood stability to neuroprotective and anti-suicidal properties. Its use in bipolar disorder is under-appreciated, particularly as it has the best evidence for prophylaxis, qualifying it perhaps as the only true mood stabilizer currently available. In practice, its risks and tolerability are exaggerated and can be readily minimized with knowledge of its clinical profile and judicious application.

Conclusion: Lithium is a safe and effective agent that should, whenever indicated, be used first-line for the treatment of bipolar disorder. A better understanding of its science alongside strategic management of its plasma levels will ensure both wider utility and improved outcomes.