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N7-(carboxymethyl)guanine-Lithium Crystalline Complex: A Bioinspired Solid Electrolyte.

Dutta D, Nagapradeep N, Zhu H, Forsyth M, Verma S, Bhattacharyya AJ - Sci Rep (2016)

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore-560012 (Karnataka), India.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus

Synthesis of G7Li from 1. (right) guanine-guanine hydrogen bond interactionsin G7Li.Inset: distorted tetrahedral geometry of Li ion in G7Li.
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f1: Synthesis of G7Li from 1. (right) guanine-guanine hydrogen bond interactionsin G7Li.Inset: distorted tetrahedral geometry of Li ion in G7Li.

Mentions: Complexation of N7-(carboxymethyl)guanine (1) withLiOH·H2O, followed by slow evaporation resulted incolorless crystals of G7Li (c/f Tables S1 andS2 in the Supplementary Information, ESI). Single crystal X-ray analysisreveals that G7Li crystallized in monoclinic space group P21/c andthe asymmetric unit composed of an anionic guanine derivative (1), one Li-ionand three water molecules in which 1 and the water molecules are directlybound to the lithium ion revealing a distorted tetrahedral geometry(Li1O1 = 1.933 Å). Notably, modifiedguanine moieties interacted through the Watson−Crick face and theextended sugar edge, due to the availability of free N9 acceptor site. Theseinteractions are supported by six hydrogen bonds(N2−H2B…N9 = 1.992 Å;N2−H2A…O6 = 2.185 Å;N1−H1…N3 = 2.011 Å)(Fig. 1), resulting in the formation of infinite guanineribbons, when viewed along the c-axis37. ThisDDA…AAD triple hydrogen bonding sequence between guanine moieties isscarce in the literature (where D = donor,A = acceptor)3839. These guanineribbons are further stabilized by π-π interactions involvingparallel offset rings and exhibited a ladder-like structure, when viewed along theb-axis (c/f Figure S1 in the ESI). Infinite array of lithium ions areobserved in the lattice when viewed along the c-axis. The lithium ions areequispaced(dLi1−Li1 = 6.991 Å,Fig. 2) and the distance between them is longer than thesum of the van der Waals radii (3.64 Å) and is obviouslylonger than the sum of ionic radii (1.86 Å)40as well. The alignment of lithium ions and the distances between them in the crystallattice (when viewed along different crystallographic directions) is furtherdepicted in Figure S2. Surprisingly, the carbonyl oxygen O6 ofguanine did not show any direct interaction with lithium ions instead interactedwith lithium bound water molecules which in turn connected through carboxylateoxygens (c/f Figures S3 and S4). Thus the G7Li on one hand strongly resembles aceramic Li-ion conductor to a great extent in terms of physical appearance (in theform of powder with a lower melting temperature). On the other hand, the G7Li alsoresembles an ionomer due to the built-in Li+-ions in the intrinsicstructure. These Li-ions are expected to sustain Li+-ion transportand no extra addition of Li-salt is required. This is an added advantage overpolymer electrolytes where additional Li-salt has to be added to sustainconductivity.


N7-(carboxymethyl)guanine-Lithium Crystalline Complex: A Bioinspired Solid Electrolyte.

Dutta D, Nagapradeep N, Zhu H, Forsyth M, Verma S, Bhattacharyya AJ - Sci Rep (2016)

Synthesis of G7Li from 1. (right) guanine-guanine hydrogen bond interactionsin G7Li.Inset: distorted tetrahedral geometry of Li ion in G7Li.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835778&req=5

f1: Synthesis of G7Li from 1. (right) guanine-guanine hydrogen bond interactionsin G7Li.Inset: distorted tetrahedral geometry of Li ion in G7Li.
Mentions: Complexation of N7-(carboxymethyl)guanine (1) withLiOH·H2O, followed by slow evaporation resulted incolorless crystals of G7Li (c/f Tables S1 andS2 in the Supplementary Information, ESI). Single crystal X-ray analysisreveals that G7Li crystallized in monoclinic space group P21/c andthe asymmetric unit composed of an anionic guanine derivative (1), one Li-ionand three water molecules in which 1 and the water molecules are directlybound to the lithium ion revealing a distorted tetrahedral geometry(Li1O1 = 1.933 Å). Notably, modifiedguanine moieties interacted through the Watson−Crick face and theextended sugar edge, due to the availability of free N9 acceptor site. Theseinteractions are supported by six hydrogen bonds(N2−H2B…N9 = 1.992 Å;N2−H2A…O6 = 2.185 Å;N1−H1…N3 = 2.011 Å)(Fig. 1), resulting in the formation of infinite guanineribbons, when viewed along the c-axis37. ThisDDA…AAD triple hydrogen bonding sequence between guanine moieties isscarce in the literature (where D = donor,A = acceptor)3839. These guanineribbons are further stabilized by π-π interactions involvingparallel offset rings and exhibited a ladder-like structure, when viewed along theb-axis (c/f Figure S1 in the ESI). Infinite array of lithium ions areobserved in the lattice when viewed along the c-axis. The lithium ions areequispaced(dLi1−Li1 = 6.991 Å,Fig. 2) and the distance between them is longer than thesum of the van der Waals radii (3.64 Å) and is obviouslylonger than the sum of ionic radii (1.86 Å)40as well. The alignment of lithium ions and the distances between them in the crystallattice (when viewed along different crystallographic directions) is furtherdepicted in Figure S2. Surprisingly, the carbonyl oxygen O6 ofguanine did not show any direct interaction with lithium ions instead interactedwith lithium bound water molecules which in turn connected through carboxylateoxygens (c/f Figures S3 and S4). Thus the G7Li on one hand strongly resembles aceramic Li-ion conductor to a great extent in terms of physical appearance (in theform of powder with a lower melting temperature). On the other hand, the G7Li alsoresembles an ionomer due to the built-in Li+-ions in the intrinsicstructure. These Li-ions are expected to sustain Li+-ion transportand no extra addition of Li-salt is required. This is an added advantage overpolymer electrolytes where additional Li-salt has to be added to sustainconductivity.

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore-560012 (Karnataka), India.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus