skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • NSF Public Access
  • Search Results
  • Alkali Metal Carbatrane Compounds [Tism PriBenz ]M: Synthesis and Structural Characterization of a Complete Series of Monomeric Alkali Metal Alkyl Compounds
Title: Alkali Metal Carbatrane Compounds [Tism PriBenz ]M: Synthesis and Structural Characterization of a Complete Series of Monomeric Alkali Metal Alkyl Compounds
The tris[(1-isopropylbenzimidazol-2-yl)dimethylsilyl]methyl thallium compound, [TismPriBenz]Tl, reacts with Li, Na, K and Rb afford the respective alkali metal carbatrane complex, [TismPriBenz]M (M = Li, Na, K, Rb), while the cesium complex [TismPriBenz]Cs is obtained via the reaction of [TismPriBenz]Li with CsF. These carbatrane compounds [TismPriBenz]M (M = Li, Na, K, Rb and Cs) constitute the first complete series of structurally characterized monomeric alkyl compounds of the nonradioactive alkali metals.  more » « less
Award ID(s):
1955648
PAR ID:
10509980
Author(s) / Creator(s):
;
Publisher / Repository:
Organometallics
Date Published:
Journal Name:
Organometallics
Volume:
42
Issue:
22
ISSN:
0276-7333
Page Range / eLocation ID:
3208 to 3218
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; ; (, Chemical Communications)
    null (Ed.)
    The reactivity of alkali metal capped Ce( iv ) imido compounds [M(DME) 2 ][CeNAr F (TriNOx)] ( 1-M with M = K, Rb, Cs and Ar F = 3,5-bis(trifluoromethyl)phenyl) with CO 2 and organic isocyanates has been evaluated. 1-Cs reacted with CO 2 to yield an organocarbamate complex. Reaction of 1-K and 1-Rb with organic isocyanates yielded organoureate Ce( iv ) complexes. 
    more » « less
  2. ; ; ; ; ; (, Physical Chemistry Chemical Physics)
    The gas-phase structures of cationized glycine (Gly), including complexes with Li + , Na + , K + , Rb + , and Cs + , are examined using infrared multiple-photon dissociation (IRMPD) spectroscopy utilizing light generated by a free electron laser, in conjunction with ab initio calculations. To identify the structures present in the experimental studies, measured IRMPD spectra are compared to spectra calculated at B3LYP/6-311+G(d,p) for the Li + , Na + , and K + complexes and at B3LYP/def2TZVP for the Rb + and Cs + complexes. Single-point energy calculations were carried out at the B3LYP, B3P86, and MP2(full) levels using the 6-311+G(2d,2p) basis set for Li + , Na + , K + and the def2TZVPP basis set for Rb + and Cs + . The Li + and Na + complexes are identified as metal cation coordination to the amino nitrogen and carbonyl oxygen, [N,CO]-tt, although Na + (Gly) may have contributions from additional structures. The heavier metal cations coordinate to either the carbonyl oxygen, [CO]-cc, or the carbonyl oxygen and hydroxy oxygen, [CO,OH]-cc, with the former apparently preferred for Rb + and Cs + and the latter for K + . These two structures reside in a double-well potential and different levels of theory predict very different relative stabilities. Some experimental evidence is provided that MP2(full) theory provides the most accurate relative energies. 
    more » « less
  3. ; ; ; ; ; ; ; ; ; ; et al (, Advanced Energy Materials)
    Abstract Graphite anodes offer low volumetric capacity in lithium‐ion batteries. By contrast, tellurene is expected to alloy with alkali metals with high volumetric capacity (≈2620 mAh cm−3), but to date there is no detailed study on its alloying behavior. In this work, the alloying response of a range of alkali metals (A = Li, Na, or K) with few‐layer Te is investigated. In situ transmission electron microscopy and density functional theory both indicate that Te alloys with alkali metals forming A2Te. However, the crystalline order of alloyed products varies significantly from single‐crystal (for Li2Te) to polycrystalline (for Na2Te and K2Te). Typical alloying materials lose their crystallinity when reacted with Li—the ability of Te to retain its crystallinity is therefore surprising. Simulations reveal that compared to Na or K, the migration of Li is highly “isotropic” in Te, enabling its crystallinity to be preserved. Such isotropic Li transport is made possible by Te's peculiar structure comprising chiral‐chains bound by van der Waals forces. While alloying with Na and K show poor performance, with Li, Te exhibits a stable volumetric capacity of ≈700 mAh cm−3, which is about twice the practical capacity of commercial graphite. 
    more » « less
  4. ; ; ; ; ; (, Chemistry – An Asian Journal)
    Abstract The two‐fold reduction of tetrabenzo[a,c,e,g]cyclooctatetraene (TBCOT, or tetraphenylene,1) with K, Rb, and Cs metals reveals a distinctive core transformation pathway: a newly formed C−C bond converts the central eight‐membered ring into a twisted core with two fused five‐membered rings. This C−C bond of 1.589(3)–1.606(6) Å falls into a single σ‐bond range and generates two perpendicular π‐surfaces with dihedral angles of 110.3(9)°–117.4(1)° in the1TR2−dianions. As a result, the highly contorted1TR2−ligand exhibits a “butterfly” shape and could provide different coordination sites for metal‐ion binding. The K‐induced reduction of1in THF affords a polymeric product with low solubility, namely [{K+(THF)}2(1TR2−)] (K2‐1TR2−). The use of a secondary ligand facilitates the isolation of discrete complexes with heavy alkali metals, [Rb+(18‐crown‐6)]2[1TR2−] (Rb2‐1TR2−) and [Cs+(18‐crown‐6)]2[1TR2−] (Cs2‐1TR2−). Both internal and external coordination are observed inK2‐1TR2−, while the bulky 18‐crown‐6 ligand only allows external metal binding inRb2‐1TR2−andCs2‐1TR2−. The reversibility of the two‐fold reduction and bond rearrangement is demonstrated by NMR spectroscopy. Computational analysis shows that the heavier alkali metals enable effective charge transfer from the1TR2−TBCOT dianion, however, the aromaticity of the polycyclic ligand remains largely unaffected. 
    more » « less
  5. ; ; ; ; ; ; ; (, Small)
    Abstract Organic materials with redox‐active oxygen functional groups are of great interest as electrode materials for alkali‐ion storage due to their earth‐abundant constituents, structural tunability, and enhanced energy storage properties. Herein, a hybrid carbon framework consisting of reduced graphene oxide and oxygen functionalized carbon quantum dots (CQDs) is developed via the one‐pot solvothermal reduction method, and a systematic study is undertaken to investigate its redox mechanism and electrochemical properties with Li‐, Na‐, and K‐ions. Due to the incorporation of CQDs, the hybrid cathode delivers consistent improvements in charge storage performance for the alkali‐ions and impressive reversible capacity (257 mAh g−1at 50 mA g−1), rate capability (111 mAh g−1at 1 A g−1), and cycling stability (79% retention after 10 000 cycles) with Li‐ion. Furthermore, density functional theory calculations uncover the CQD structure‐electrochemical reactivity trends for different alkali‐ion. The results provide important insights into adopting CQD species for optimal alkali‐ion storage. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email