2,2':6',2''-Terpyridine as Monodentate Ligand: Halogen Bonding Driven Formation of Discrete 2 : 1 Aggregates with 1,2,4,5-Tetrafluoro-3,6-diiodobenzene

2002 ◽  
Vol 67 (9) ◽  
pp. 1373-1382 ◽  
Author(s):  
Rosalba Liantonio ◽  
Thomas A. Logothetis ◽  
Maria T. Messina ◽  
Pierangelo Metrangolo ◽  
Alessandra De Santis ◽  
...  
Keyword(s):  
Coordination Chemistry ◽  
Electron Donor ◽  
Room Temperature ◽  
Solid Phase ◽  
Halogen Bonding ◽  
Electron Donors ◽  
Tridentate Ligand ◽  
Supramolecular Systems ◽  
Monodentate Ligand ◽  
X Ray

2,2':6',2''-Terpyridine (1) is a well-known electron donor module in metal coordination chemistry and typically works as a tridentate ligand. Here it is shown that 1 can also work as electron donor towards iodoperfluorocarbons both in solution and in the solid phase. Halogen-bonded supramolecular systems are thus obtained. Specifically, terpyridine 1 self-assembles with 1,2,4,5-tetrafluoro-3,6-diiodobenzene (2) and affords the trimeric adduct 3, which is stable and crystalline in the air at room temperature. Single crystal X-ray analysis shows how in adduct 3 both iodine atoms of one molecule of 2 are halogen-bonded to the nitrogen atoms of external pyridine rings of two molecules of 1 that act as monodentate electron donors.

THE SYSTEM: BISMUTH–CADMIUM–MERCURY

1965 ◽  
Vol 43 (7) ◽  
pp. 1924-1928 ◽  
Author(s):  
A. N. Campbell ◽  
E. M. Kartzmark
Keyword(s):  
Binary System ◽  
Ternary Alloy ◽  
Room Temperature ◽  
Solid Phase ◽  
Liquidus Surface ◽  
Molar Volumes ◽  
X Ray

The liquidus surface of this ternary alloy has been determined, together with the nature of the solid phase separating from various melts. The densities and molar volumes of the binary system: Cd—Hg have been determined and it is shown that there is marked contraction when the α and β phases form from the components. X-ray powder photographs of various Cd—Hg alloys at room temperature have been made and the limits of homogeneity determined.

Syntheses, Structures, Thermal and Photoluminescence Properties of Two Zn(II) and Cd(II) Coordination Polymers Constructed from Taurine-derived Schiff Base and 4,4’-Bipyridine Ligands

2012 ◽  
Vol 67 (8) ◽  
pp. 774-782 ◽  
Author(s):  
Wei-Ting Guo ◽  
Zhi-Min Miao ◽  
Yun-Long Wang
Keyword(s):  
Schiff Base ◽  
Coordination Polymers ◽  
Tridentate Ligand ◽  
Supramolecular Architecture ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Monodentate Ligand ◽  
Metal Centers ◽  
X Ray ◽  
Ethanesulfonic Acid

Two chain-like coordination polymers, namely, {[Zn(saes)(4,4'-bipy)(H2O)]·H2O}n (1) and {[Cd (Hsaes)2(4,4'-bipy)(H2O)2]·2H2O}n (2), where H2saes=2-(2-hydroxybenzylideneamino)ethanesulfonic acid and 4,4'-bipy=4,4'-bipyridine, have been synthesized and characterized by singlecrystal X-ray diffraction, IR spectroscopy, elemental, thermogravimetric and photoluminescence analysis. X-Ray diffraction analyses indicate that 1and 2display octahedral metal centers with N3O3 and N2O4 donor sets, respectively. The Schiff base serves as a common N,O'-tridentate ligand in 1, and as a unique O-monodentate ligand in 2. In the crystal, both 1and 2form a 3D supramolecular architecture by O-H···O, C-H···O interactions or π···π stacking. The thermal and solid-state photoluminescence properties of both complexes have been investigated

Solid-Solid Phase Transition in Trimethylolpropane (TRMP)

2002 ◽  
Vol 216 (12) ◽  
Author(s):  
D. Chandra ◽  
H. Mandalia ◽  
W.-M. Chien ◽  
D. W. Lindle ◽  
R. Rudman
Keyword(s):  
Room Temperature ◽  
Solid Phase ◽  
X Ray Diffraction ◽  
Storage Material ◽  
X Ray ◽  
Α Phase ◽  
Energy Storage Material ◽  
Plastic Phase ◽  
Solid Phase Transition ◽  
Thermal Energy Storage Material

An orientationally disordered crystalline (ODIC) plastic phase (γ) was observed in Trimethylolpropane (TRMP) during heating by high resolution thermal and X-ray diffraction analyses. TRMP is a potential thermal energy storage material. The enthalpies of solid-solid (α → γ at 327.8 K) and fusion (γ → liquid at 332.7 K) transitions are 16.36 kJ/mol and 0.9 kJ/mol, respectively. Supercooling was observed during solidification of melts, and this supercooled γ phase began to transform to a metastable crystalline phase, designated as α′, after 20 minutes at room temperature. The lattice parameters of the monoclinic α phase, obtained from this study, are:

scholarly journals Получение, структура, диэлектрические и магнитные свойства керамики SrFe-=SUB=-2/3-=/SUB=-W-=SUB=-1/3-=/SUB=-O-=SUB=-3-=/SUB=-

2018 ◽  
Vol 60 (3) ◽  
pp. 510
Author(s):  
А.В. Павленко ◽  
А.В. Турик ◽  
Л.А. Шилкина ◽  
С.П. Кубрин ◽  
Ю.B. Русалев ◽  
...  
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Solid Phase ◽  
Ceramic Technology ◽  
Tetragonal Symmetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid Phase Reactions ◽  
Perovskite Type ◽  
Perovskite Type Structure

AbstractPolycrystalline samples of SrFe_2/3W_1/3O_3 (SFWO) ceramic were obtained by solid-phase reactions with subsequent sintering using conventional ceramic technology. X-ray diffraction analysis showed that at room temperature, the SFWO ceramic is single-phase and has a perovskite-type structure with tetragonal symmetry and parameters a = 3.941(9) Å, c = 3.955(6) Å, and c/a = 1.0035. In studying the magnetic properties and the Mössbauer effect in SFWO ceramics, it is found that the material is a ferrimagnet, and the iron ions are only in the valence state of Fe^3+. It is suggested that in the temperature range of T = 150–210°C, a smeared phase transition from a cubic (paraelectric) phase to a tetragonal (ferroelectric) phase takes place in SFWO with decreasing temperature.

Metal Complexes of 1,3-Bis(Pyridin-2-yl)pyrazole: Spectral, Magnetic and Structural Studies

1995 ◽  
Vol 48 (6) ◽  
pp. 1071 ◽  
Author(s):  
AT Baker ◽  
DC Craig ◽  
G Dong ◽  
AD Rae
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
Complex Cation ◽  
Tridentate Ligand ◽  
Structural Studies ◽  
Crystal Data ◽  
Octahedral Structure ◽  
Heterocyclic Ligands ◽  
X Ray ◽  
Donor Nitrogen

Bis(ligand)iron(II) and nickel(II) complexes of the asymmetric tridentate ligand 1,3-bis(pyridin-2-yl) pyrazole , L, have been prepared. The iron(II) complex, [FeL2] [PF6]2, is high-spin in the solid state over the temperature range 304-102 K, with a magnetic moment of 5.27 BM at room temperature. The crystal structure of bis (1,3-bis(pyridin-2-yl) pyrazole )iron(II) bis (hexafluorophosphate ) has been determined by single-crystal X-ray diffractometry. The compound crystallized as yellow prisms, with the structure being disordered in the tetragonal space group P421c with Z = 2. Crystal data a = b = 8.785(1) Ǻ, c = 19.804(6) Ǻ. The iron(II) centre is in an N6 environment, where the six donor nitrogen atoms are provided by the two tridentate heterocyclic ligands. The complex cation has an approximately octahedral structure exhibiting tetragonal compression. The observed Fe-N(pyridine) and Fe-N( pyrazole ) distances are 2.308(4) and 2.019(7) Ǻ respectively, with the Fe-N(pyridine) distance being the longest observed to date.

Study of Electrical and Aging Properties on the La-Doped Aurivillius Phase Ferroelectrics BaBi4Ti4O15

2013 ◽  
Vol 319 ◽  
pp. 9-13
Author(s):  
Bai Wei Yu ◽  
Qian Qian Zheng ◽  
Li Jing Pan ◽  
Dong Hua Zhang ◽  
Yan Xue Tang ◽  
...  
Keyword(s):  
Relative Permittivity ◽  
Marked Improvement ◽  
Room Temperature ◽  
Solid Phase ◽  
X Ray Diffraction ◽  
Aurivillius Phase ◽  
X Ray ◽  
Aging Properties ◽  
T Phase ◽  
La Doped

Aurivillius phase ferroelectrics Ba(Bi1−xLax)4Ti4O15(x=0-0.05) (BBiLxT) was synthesized by a modified high-temperature solid-phase route.The structure, the dielectric, the ferroelectric and the aging properties were investigated systematically. With the La3+doping, the room temperature relative permittivity of the samples is increased, and dielectric loss is decreased. For the BBiLxT phase, only a weak variation with respect to the F2mm space group can be suggested from single crystal X-ray diffraction. The microstructure confirms the samples have a well-proportioned grain size and a higher density. The substitution also results in a marked improvement in the remnant polarization. The doping of La3+in BBiLxT ceramics increased the room temperature relative permittivity aging properties.

Untersuchungen zur Polymorphie der Cäsium-Dodekahalogeno-closo-Dodekaborate Cs2[B12X12] (X = Cl–I)

2020 ◽  
Vol 75 (8) ◽  
pp. 777-790
Author(s):  
Ioannis Tiritiris ◽  
Kevin U. Bareiß ◽  
Thomas Schleid
Keyword(s):  
Phase Transitions ◽  
Defect Structure ◽  
Room Temperature ◽  
Solid Phase ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Space Group ◽  
X Ray ◽  
Cubic System ◽  
Cesium Salts

AbstractThermoanalytic DSC and temperature-dependent X-ray diffraction investigations on the cesium dodecahalogeno-closo-dodecaborates Cs2[B12X12] (X = Cl–I) have revealed solid-solid phase transitions from their trigonal room-temperature α-forms (e.g. α-Cs2[B12Cl12]: a = 959.67(3) pm, c = 4564.2(2) pm, Z = 6, space group R$\overline{3}$) into cubic high-temperature modifications. The isotypic title compounds crystallize in the space group Pm$\overline{3}$n (e.g. β-Cs2[B12Cl12]: a = 1051.98(6) pm, Z = 2) with a W3O-type defect structure. The statistic occupation of six possible positions with only four Cs+ cations results in a cation-deficient A2B arrangement for Cs2[B12X12]. Upon cooling the β-phase, a third polymorph was observed, which also crystallizes in the cubic system, but now in the space group Ia$\overline{3}$d (e.g. γ-Cs2[B12Cl12]: a = 2102.2(3) pm, Z = 16), and has to be regarded as a phase with only a partially disordered cation substructure. In this crystal structure the [B12X12]2− anions exhibit a NaTl-type arrangement, in which the Cs+ cations occupy suitable interstices. The phase transitions of the differently halogenated cesium salts follow no specific trend as the transition from the trigonal α- to the cubic β-form occurs at 178 °C for the chlorinated, at 270 °C for the iodinated and at 325 °C for the brominated examples. On further heating however, β-Cs2[B12I12] starts to decompose at 945 °C first, followed by β-Cs2[B12Br12] and β-Cs2[B12Cl12] at 959 °C and 983 °C, respectively.

X-ray powder diffraction investigation of new high temperature polymorphs of CaTeO3 and CaTe2O5

2001 ◽  
Vol 16 (4) ◽  
pp. 205-211 ◽  
Author(s):  
S. N. Tripathi ◽  
R. Mishra ◽  
M. D. Mathews ◽  
P. N. Namboodiri
Keyword(s):  
High Temperature ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Solid Phase ◽  
High Temperature Phase ◽  
Unit Cell ◽  
Stable Phase ◽  
Temperature Phase ◽  
X Ray ◽  
Monoclinic Lattice

X-ray powder diffraction investigation of the new high temperature polymorphs beta- and gamma-CaTeO3 and gamma- and delta-CaTe2O5 and picnometric measurements of the room temperature phases of the two compounds have been carried out. The study led to the elucidation of their unit cell structures and assignment of entirely new lattice types and parameters to the room temperature phases of CaTeO3 and CaTe2O5 in contrast and supersession to the existing structural information. The results are as follows: CaTeO3 has only one stable phase at room temperature and temperatures up to 882 °C, i.e., α- and has a triclinic unit cell with a=4.132±0.003 Å, b=6.120±0.006 Å, c=12.836±0.013 Å, α=121.80°, β=99.72°, γ=97.26°. The first high temperature phase stable between 882 and 894 °C, i.e., β-CaTeO3, has a monoclinic lattice: a=20.577±0.007 Å, b=21.857±0.009 Å, c=4.111±0.002 Å, β=96.15°, while the next phase stable above 894 °C, i.e., γ-CaTeO3, has a hexagonal unit cell with parameters: a=14.015±0.0001 Å, c=9.783±0.001 Å, c/a=0.698. CaTe2O5 has one stable phase at temperatures up to 802 °C, i.e., α-CaTe2O5 with a monoclinic lattice and parameters: a=9.069±0.002 Å, b=25.175±0.007 Å, c=3.366±0.001 Å, β=98.29 °. The first high temperature phase stable in the range 802–845°, i.e., β-CaTe2O5, is monoclinic with unit cell parameters: a=4.146±0.001 Å, b=5.334±0.002 Å, c=6.105±0.002 Å, β=98.362 °; the next higher temperature phase stable over 845–857 °C, i.e., γ-CaTe2O5, has an orthorhombic unit cell with: a=8.638±0.001 Å, b=9.291±0.001 Å, c=7.862±0.001 Å and the highest temperature solid phase stable above 857 °C, i.e., δ-CaTe2O5 has a tetragonal unit cell with a=5.764±0.000 Å, c=32.074±0.020 Å, c/a=5.5637.

A Silver(I) Coordination Polymer Based on a Schiff Base Ligand: Synthesis, Crystal Structure and Luminescence Properties

2013 ◽  
Vol 68 (3) ◽  
pp. 284-288 ◽  
Author(s):  
Lin Yu Jin ◽  
Meng Meng Li ◽  
Dong Bin Dang ◽  
Yan Bai ◽  
Yan Ning Zheng
Keyword(s):  
Coordination Polymer ◽  
Room Temperature ◽  
Three Dimensional ◽  
Chain Structure ◽  
Luminescence Properties ◽  
Tridentate Ligand ◽  
Supramolecular Network ◽  
Zigzag Chain ◽  
X Ray Diffraction ◽  
X Ray

A new Ag(I) coordination polymer [AgL(NO3)]n 1 (L=4-(pyridine-2-yl)methyleneamino-1,2,4- trizaole) has been synthesized and characterized by IR spectroscopy, elemental analysis, powder and single-crystal X-ray diffraction. The Ag(I) atom has a seesaw environment with an N3O donor set from three N atoms of two ligands and one O atom of one NO-3 anion. Each twisted tridentate ligand is bound to two silver centers, and each silver atom is coordinated by two ligands thereby generating a zigzag chain structure. The chains interact with each other featuring a three-dimensional supramolecular network through multiple weak C-H···π interactions and C-H···O hydrogen bonds. The luminescence properties of the polymer 1 were investigated in the solid state at room temperature.

Vanadium and niobium diamidophosphine complexes and their reactivity

2003 ◽  
Vol 81 (12) ◽  
pp. 1431-1437 ◽  
Author(s):  
Michael P Shaver ◽  
Robert K Thomson ◽  
Brian O Patrick ◽  
Michael D Fryzuk
Keyword(s):  
Coordination Chemistry ◽  
Solid State ◽  
Molecular Nitrogen ◽  
Tridentate Ligand ◽  
State Structure ◽  
Butyl Lithium ◽  
Solid State Structure ◽  
X Ray ◽  
X Ray Crystallography ◽  
Unstable Complex

The tridentate ligand precursors R′P(CH2SiMe2NR′′)2 (R′R′′[NPN]: R′ = Cy, Ph; R′′ = Ph, Mes, Me) were prepared from metathesis reactions of a lithiated amine, chloro(chloromethyl)dimethylsilane, the appropriate 1° phosphine, and n-butyl lithium and were isolated as solvent adducts. Metathesis between CyPh[NPN]Li2(OEt2), 2, and VCl3(THF)3 afforded (CyPh[NPN]VCl)2, 7, whose solid-state structure was established by X-ray crystallography. Reduction attempts of the (R′R′′[NPN]VCl)2 species with KC8 incorporated molecular nitrogen but were complicated by imide formation and ligand decomposition. Metathesis of 2 with NbCl2Me3 afforded the highly unstable complex CyPh[NPN]NbMe3, 15. Attempts to hydrogenate this species were unsuccessful.Key words: vanadium, niobium, metathesis, coordination chemistry, reduction, hydrogenation.

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