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Title: Conducting Molecular Nanomagnet of Dy III with Partially Charged TCNQ Radicals

Authors:
ORCiD logo [1];  [1];  [1];  [1]; ORCiD logo [1]
  1. Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station TX 77842-3012 USA
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1400625
Grant/Contract Number:
AC02-06CH11357; SC0012582
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Chemistry - A European Journal
Additional Journal Information:
Journal Volume: 23; Journal Issue: 31; Related Information: CHORUS Timestamp: 2017-10-20 15:19:11; Journal ID: ISSN 0947-6539
Publisher:
Wiley Blackwell (John Wiley & Sons)
Country of Publication:
Germany
Language:
English

Citation Formats

Zhang, Xuan, Xie, Haomiao, Ballesteros-Rivas, Maria, Woods, Toby J., and Dunbar, Kim R.. Conducting Molecular Nanomagnet of Dy III with Partially Charged TCNQ Radicals. Germany: N. p., 2017. Web. doi:10.1002/chem.201701590.
Zhang, Xuan, Xie, Haomiao, Ballesteros-Rivas, Maria, Woods, Toby J., & Dunbar, Kim R.. Conducting Molecular Nanomagnet of Dy III with Partially Charged TCNQ Radicals. Germany. doi:10.1002/chem.201701590.
Zhang, Xuan, Xie, Haomiao, Ballesteros-Rivas, Maria, Woods, Toby J., and Dunbar, Kim R.. 2017. "Conducting Molecular Nanomagnet of Dy III with Partially Charged TCNQ Radicals". Germany. doi:10.1002/chem.201701590.
@article{osti_1400625,
title = {Conducting Molecular Nanomagnet of Dy III with Partially Charged TCNQ Radicals},
author = {Zhang, Xuan and Xie, Haomiao and Ballesteros-Rivas, Maria and Woods, Toby J. and Dunbar, Kim R.},
abstractNote = {},
doi = {10.1002/chem.201701590},
journal = {Chemistry - A European Journal},
number = 31,
volume = 23,
place = {Germany},
year = 2017,
month = 5
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on May 10, 2018
Publisher's Accepted Manuscript

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  • Potassium tetracyanoplatinate(II) trihydrate, K/sub 2/Pt(CN)/sub 4/.3H/sub 2/O, crystallizes in the orthorhombic space group Pbcn, with a = 13.426 (5), b = 11.848 (4), and c = 6.956 (2) A with Z = 4. The strongly efflorescent crystals grown from aqueous solution were sealed in capillaries for three-dimensional neutron data collection. The structure was deduced from the neutron Patterson map and was refined by Fourier and full-matrix least-squares techniques to R/sub F/sup 2// = 0.061 (R/sub F/ = 0.056) for 587 reflections with F/sup 2/ > sigma(F/sup 2/). The structure consists of planar Pt(CN)/sub 4//sup 2 -/ groups stacked parallel tomore » c forming linear Pt chains with a Pt-Pt separation of 3.478 (1) A. Alternate Pt(CN)/sub 4//sup 2 -/ groups are rotated giving an eclipsed configuration with C-Pt-Pt-C torsion angles of 15.7 (1) and 16.7 (1)/sup 0/. The Pt(CN)/sub 4//sup 2 -/ plane is also tilted with respect to c by approx.3/sup 0/. The two types of water molecules serve to link Cn/sup -/ groups within a Pt(CN)/sub 4//sup 2 -/ stack and to cross-link adjacent Pt(CN)/sub 4//sup 2 -/ stacks. Comparisons are made with the structure of the mixed-valence compound K/sub 2/Pt(CN)/sub 4/Bro.3.3H/sub 2/O, KCP(Br). (auth)« less
  • Pyrazino-TCNQ (1a) prepared from 5, 8-diiodoquinoxaline (4a) is, like TCNQ itself, a strong electron acceptor and gives a stable anion radical salt as well as highly conductive charge-transfer crystals with donors. Substituted derivatives 1b-i were similarly prepared from 3,6-diiodo- 1,2-phenylenediamine (5) as a common intermediate, and bulky substituents such as the phenyl or pyridyl groups have very little effect on either the redox properties or planar geometry of 1a. Neutral radicals 3d-g derived from pyridyl-substituted derivatives 1d-g, respectively, are open-shell donor-[pi]-acceptor systems with high electrical amphotericity designed as a new motif for single-component organic conductors. The powder conductivity of 3fmore » was as high as 3.2 [times] 10[sup [minus]5] S cm[sup [minus]1]. 29 refs., 4 figs., 2 tabs.« less
  • The magnetic molecular cluster [Fe{sub 8}(N{sub 3}C{sub 6}H{sub 15}){sub 6}O{sub 2}(OH){sub 12}]{sup 8+}[Br{sub 8}{center_dot}9H{sub 2}O]{sup 8-}, in short Fe8, has been investigated at low temperature by {sup 1}H-NMR and relaxation measurements. Some measurements of {sup 2}D-NMR in partially deuterated Fe8 clusters will also be reported. Upon decreasing temperature the NMR spectra display a very broad and structured signal which is the result of the internal local fields at the proton sites due to the local moments of the Fe(III) ions in the total S=10 magnetic ground state. The proton and deuteron NMR spectra have been analyzed and the different resonancemore » peaks have been attributed to the different proton groups in the molecule. The simulation of the spectra by using a dipolar hyperfine field and the accepted model for the orientation of the Fe(III) local moments do not agree with the experiments even when the magnitude of the local Fe(III) moments is allowed to vary. It is concluded that a positive contact hyperfine interaction of the same order of magnitude as the dipolar interaction is present for all proton sites except the water molecules. The temperature and magnetic field dependence of the nuclear spin-lattice relaxation rate is ascribed to the fluctuations of the local Fe(III) moments, which follow rigidly the fluctuations of the total ground state magnetization of the nanomagnet. By using a simple model already utilized for the Mn12 cluster, we derive the value of the spin phonon coupling constant which determines the lifetime broadening of the different magnetic quantum number m substates of the S=10 ground state. It is shown that the lifetime broadening decreases rapidly on lowering the temperature. When the lifetime becomes longer than the reciprocal of the frequency shift of the proton lines a structure emerges in the NMR spectrum reflecting the ''frozen'' local moment configuration.« less
  • This salt belongs to the monoclinic space group P2/sub 1//c/sub 1/((a = 9.7076 (12), b = 12.2113 (17), c = 23.5849 (36)); ..beta.. = 95.012 (2)/sup 0/; Z = 4; and rho = 1.265 gcm/sup -3/. The structure was determined by a combination of Patterson, direct methods, Fourier, and least-squares refinement techniques to an R/sub f/ = 0.058 for the 3042 independent observable reflections from a total of 3667 reflections collected on an automatic diffractometer. The crystalline lattice consists of isolated dimeric units of Fe(C/sub 5/Me/sub 5/)/sub 2//TCNQ/TCNQ/Fe(C/sub 5/Me/sub 5/)/sub 2/ A:B:B:A composition. The molecular structure is illustrated and discussed.more » The magnetic susceptibility of powder samples obeys the Curie expression, i.e. chi(T) = 0.81 BM. This is in accord with values obtained for other ferrocenium salts, and suggests very little magnetic coupling between the intradimer S = 1/2 Fe(III) separated by 14 A. The (TCNQ)/sub 2//sup 2 -/ dimer is strongly antiferromagnetically coupled.« less