Two Hydroxo Bridged Dinuclear Lanthanide Phen Complexes: [Ln2(phen)4(H2O)4(OH)2](phen)2(NO3)4 with Ln = Tm, Yb

AbstractTwo isostructural hydroxo bridged dinuclear lanthanide phen complexes of general composition [Ln2(phen)4(H2O)4(OH)2](phen)2(NO3)4 with Ln = Tm (1), Yb (2) were prepared by reactions of the corresponding lanthanide nitrate and phenanthroline monohydrate in CH3OH/H2O at pH = 5.5. They crystallize in the triclinic space group P1̄ (no. 2) with the cell dimensions: a = 11.233(1), b = 11.456(1), c = 14.011(2) Å , α = 93.91(1)°, β = 98.20(1)°, γ = 108.21(1)°, V = 1683.0(3)Å3, Z = 1 for 1 and a = 11.236(1), b = 11.480(2), c = 13.986(2)Å , α = 93.91(1)°, β = 98.17(1)°, γ = 108.33(1)°, V = 1682.9(3) Å3, Z = 1 for 2. The crystal structures are composed of the hydroxo bridged dinuclear [Ln2(phen)4(H2O)4(OH)4]4+ complex cations, hydrogen bonded NO3- anions and π-π stacking (phen)2 dimers. The lanthanide atoms are each surrounded by two phen ligands, two H2O molecules and two μ-OH groups to complete a tetragonal antiprismatic LnN4O4 coordination. Via two common μ-OH groups, two neighboring tetragonal antiprisms are condensed to form a centrosymmetric dinuclear [Ln2(phen)4(H2O)4(OH)4]4+ complex cation. The complex cations and (phen)2 dimers are assembled via π-π stacking interactions and hydrogen bondings into 2D layers parallel to (101̄), between which the hydrogen bonded NO3- anions are sandwiched. The Tm compound shows paramagnetic behavior with an experimental magnetic moment of 7.51 μB at room temperature. No magnetic ordering is evident down to 5 K. Over the temperature range 70 - 300 K, the Yb compound obeys the Curie-Weiss law with an experimental magnetic moment of 4.32 μB at room temperature and shows weak ferrimagnetic behavior at low temperature.

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The High-Pressure Modification of CePtSn – Synthesis, Structure, and Magnetic Properties

Zeitschrift für Naturforschung B ◽

10.1515/znb-2005-0802 ◽

2005 ◽

Vol 60 (8) ◽

pp. 821-830 ◽

Cited By ~ 29

Author(s):

Jan F. Riecken ◽

Gunter Heymann ◽

Theresa Soltner ◽

Rolf-Dieter Hoffmann ◽

Hubert Huppertz ◽

...

Keyword(s):

High Pressure ◽

Magnetic Properties ◽

High Temperature ◽

Magnetic Moment ◽

Three Dimensional ◽

Magnetic Ordering ◽

Normal Pressure ◽

Variable Parameters ◽

X Ray ◽

Experimental Magnetic Moment

The high-pressure (HP) modification of CePtSn was prepared under multianvil high-pressure (9.2 GPa) high-temperature (1325 K) conditions from the normal-pressure (NP) modification. Both modifications were investigated by powder and single crystal X-ray data: TiNiSi type, Pnma, a = 746.89(9), b = 462.88(4), c = 801.93(7) pm, wR2 = 0.0487, 452 F2 values, 20 variable parameters for NP-CePtSn, and ZrNiAl type, P6̅2m, a = 756.919(5), c = 415.166(4) pm, wR2 = 0.0546, 252 F2 values, 14 variable parameters for HP-CePtSn. Both modifications are built up from platinumcentered trigonal prisms. Together, the platinum and tin atoms form different three-dimensional [PtSn] networks in which the cerium atoms fill channels. The crystal chemistry and chemical bonding of NP- and HP-CePtSn is discussed. Susceptibility measurements of HP-CePtSn indicate Curie-Weiss behavior above 40 K with an experimental magnetic moment of 2.55(1) μB/Ce atom, indicating trivalent cerium. No magnetic ordering could be detected down to 2 K.

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Infrared spectroscopic studies of adsorption and catalysis. Part 3. Carboxylic acids and their derivatives adsorbed on silica

Canadian Journal of Chemistry ◽

10.1139/v69-362 ◽

1969 ◽

Vol 47 (12) ◽

pp. 2237-2247 ◽

Cited By ~ 41

Author(s):

R. P. Young

Keyword(s):

Acetic Acid ◽

Room Temperature ◽

Acetyl Chloride ◽

Physical Adsorption ◽

Spectroscopic Studies ◽

Esterification Reaction ◽

Oh Groups ◽

Silica Surfaces ◽

Propionyl Chloride ◽

Hydrogen Bonded

Infrared spectra in the region 4000–1300 cm−1 have been obtained of acetic acid, acetyl chloride, acetic anhydride, propionic acid, and propionyl chloride adsorbed on discs of pressed silica powder. In all cases the spectra showed the presence of both the simple hydrogen-bonded species[Formula: see text]where X = OH, Cl, or O.CO.R and Si* represents a surface silicon atom, and also chemisorbed surface ester groups R.CO.O—Si*. The latter were characterized by a νC=O frequency in the 1760–1740 cm−1 region, whereas in the case of hydrogen-bonded physical adsorption, the νC=O frequency was about 20–30 cm−1 lower than that of the same molecule in the vapor phase. At high temperatures (150–200 °C) the water or hydrogen chloride eliminated in the surface esterification reaction was desorbed, and high conversions of surface OH to surface ester groups were observed. Under these conditions the carboxylic acid was formed from both the chloride and the anhydride; the latter was also produced at room temperature from the acid chloride. A scheme is suggested for the equilibration of these compounds on hydroxylated silica surfaces. The chemisorbed ester groups were susceptible to hydrolysis by water vapor, thus regenerating the original silanol OH groups.

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Magnetic Ordering in CeZnGe

Zeitschrift für Naturforschung B ◽

10.1515/znb-2009-0321 ◽

2009 ◽

Vol 64 (3) ◽

pp. 361-364 ◽

Cited By ~ 5

Author(s):

Wilfried Hermes ◽

Rainer Pöttgen

Keyword(s):

Magnetic Susceptibility ◽

Magnetic Moment ◽

High Frequency ◽

Magnetic Ordering ◽

Type Structure ◽

Pure Sample ◽

Structure Space ◽

Phase Pure ◽

Ferromagnetic Ordering ◽

Experimental Magnetic Moment

CeZnGe crystallizes with the hexagonal YPtAs-type structure, space group P63/mmc, a = 430.0(2), c = 1678.8(10) pm. A phase-pure sample was synthesized from the elements in a sealed tantalum crucible in a high-frequency furnace. Magnetic susceptibility measurements have revealed a trivalent cerium with an experimental magnetic moment of 2.67(1) μB/Ce atom. Ferromagnetic ordering sets in at TC = 4.6(2) K.

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The Magnetic Ordering of SiCN Films Prepared by Ion Implantation

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.531-532.325 ◽

2012 ◽

Vol 531-532 ◽

pp. 325-328

Author(s):

Xu Dong Meng ◽

Fu Yang ◽

Xiao Yu Liu

Keyword(s):

Ion Implantation ◽

Spin Polarization ◽

Magnetic Moment ◽

Room Temperature ◽

Room Temperature Ferromagnetism ◽

Magnetic Ordering ◽

Local Magnetic Moment ◽

Vacancy Defects ◽

Sic Films ◽

Implantation Dosage

Room-temperature ferromagnetism was observed in the SiCN films prepared by ion implantation. The result indicates that N ion implantation dosage in the film has great effect on the observed room-temperature ferromagnetism of the films. Along with the increase of ion implantation dosage, the N ions increase and the magnetism enhances. Because of the ion implantation will cause a lot of defects on the surface of SiC films, which will induce a lot of vacancies. The C atoms are replaced by the N ions doped, the concentration of the N ions decides the charges states and spin polarizations of Si vacancy defects. Local magnetic moment is induced because of the spin polarization of the Si vacancy defects, and the films show ferromagnetic properties.Charge states and spin polarizations of silicon vacancy defects can be manipulated by N atoms which induces the ferromagnetism.

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Self-Recognizing π-π Stacking Interactions Designed for the Generation of Ultrastable Mesoporous Hydrogen-Bonded Organic Frameworks

10.26434/chemrxiv.9729494 ◽

2019 ◽

Author(s):

KAIKAI MA ◽

Peng Li ◽

John Xin ◽

Yongwei Chen ◽

Zhijie Chen ◽

...

Keyword(s):

Pore Size ◽

Fiber Composite ◽

Aqueous Media ◽

Stacking Interactions ◽

Mustard Gas ◽

X Ray Diffraction ◽

X Ray ◽

Expansion Strategy ◽

Π Stacking ◽

Hydrogen Bonded

Creating crystalline porous materials with large pores is typically challenging due to undesired interpen-etration, staggered stacking, or weakened framework stability. Here, we report a pore size expansion strategy by self-recognizing π-π stacking interactions in a series of two-dimensional (2D) hydrogen–bonded organic frameworks (HOFs), HOF-10x (x=0,1,2), self-assembled from pyrene-based tectons with systematic elongation of π-conjugated molecular arms. This strategy successfully avoids interpene-tration or staggered stacking and expands the pore size of HOF materials to access mesoporous HOF-102, which features a surface area of ~ 2,500 m2/g and the largest pore volume (1.3 cm3/g) to date among all reported HOFs. More importantly, HOF-102 shows significantly enhanced thermal and chemical stability as evidenced by powder x-ray diffraction and N2 isotherms after treatments in chal-lenging conditions. Such stability enables the adsorption of dyes and cytochrome c from aqueous media by HOF-102 and affords a processible HOF-102/fiber composite for the efficient photochemical detox-ification of a mustard gas simulant.

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Achieving Long Lifetime of Pure Organic Room-temperature Phosphorescence via Constructing Hydrogen-bonded Organic Frameworks

Journal of Luminescence ◽

10.1016/j.jlumin.2021.118120 ◽

2021 ◽

pp. 118120

Author(s):

Shenghui Han ◽

Gang Lian ◽

Xu Zhang ◽

Zhaozhen Cao ◽

Qilong Wang ◽

...

Keyword(s):

Room Temperature ◽

Room Temperature Phosphorescence ◽

Long Lifetime ◽

Hydrogen Bonded

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A (111)-ordered Sr2FeRuO6 superlattice displays room-temperature magnetic ordering

MRS Bulletin ◽

10.1557/mrs.2011.161 ◽

2011 ◽

Vol 36 (7) ◽

pp. 478-478

Author(s):

Steven Spurgeon

Keyword(s):

Room Temperature ◽

Magnetic Ordering

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Molecule-Based Magnets—An Overview

MRS Bulletin ◽

10.1557/mrs2000.221 ◽

2000 ◽

Vol 25 (11) ◽

pp. 21-30 ◽

Cited By ~ 115

Author(s):

Joel S. Miller ◽

Arthur J. Epstein

Keyword(s):

Low Temperature ◽

Vapor Deposition ◽

Room Temperature ◽

Chemical Vapor ◽

Magnetic Ordering ◽

Low Density ◽

Materials Properties ◽

The Common ◽

New Processing ◽

Very High

Molecule-based magnets are a broad, emerging class of magnetic materials that expand the materials properties typically associated with magnets to include low density, transparency, electrical insulation, and low-temperature fabrication, as well as combine magnetic ordering with other properties such as photoresponsiveness. Essentially all of the common magnetic phenomena associated with conventional transition-metal and rare-earth-based magnets can be found in molecule-based magnets. Although discovered less than two decades ago, magnets with ordering temperatures exceeding room temperature, very high (∼27.0 kOe or 2.16 MA/m) and very low (several Oe or less) coercivities, and substantial remanent and saturation magnetizations have been achieved. In addition, exotic phenomena including photoresponsiveness have been reported. The advent of molecule-based magnets offers new processing opportunities. For example, thin-film magnets can be prepared by means of low-temperature chemical vapor deposition and electrodeposition methods.

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