scholarly journals Novel Lanthanide (III) Complexes Derived from an Imidazole–Biphenyl–Carboxylate Ligand: Synthesis, Structure and Luminescence Properties

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6942
Author(s):  
Monica-Cornelia Sardaru ◽  
Narcisa Laura Marangoci ◽  
Sergiu Shova ◽  
Dana Bejan

A series of neutral mononuclear lanthanide complexes [Ln(HL)2(NO3)3] (Ln = La, Ce, Nd, Eu, Gd, Dy, Ho) with rigid bidentate ligand, HL (4′-(1H-imidazol-1-yl)biphenyl-4-carboxylic acid) were synthesized under solvothermal conditions. The coordination compounds have been characterized by infrared spectroscopy, thermogravimetry, powder X-ray diffraction and elemental analysis. According to X-ray diffraction, all the complexes are a series of isostructural compounds crystallized in the P2/n monoclinic space group. Additionally, solid-state luminescence measurements of all complexes show that [Eu(HL)2(NO3)3] complex displays the characteristic emission peaks of Eu(III) ion at 593, 597, 615, and 651 nm.

1987 ◽  
Vol 40 (5) ◽  
pp. 981 ◽  
Author(s):  
WH Chan ◽  
TCW Mak ◽  
WH Yip ◽  
CHL Kennard ◽  
G Smith ◽  
...  

.The crystal structure of the anhydrous zinc(11) complex of 2-methyl-2-(phenylthio) propanoic acid, with formula [Zn2(C10H12O2)4]n, has been determined by X-ray diffraction at 20�C and refined to a residual R 0.041 for 2885 observed reflections. Crystals are monoclinic, space group P 21, with two diper units of the polymer in a unit cell with dimensions a 12.710(4), b 13.760(2), c 12.699(6) �, β 95.44(5)�. The polymer structure is based on a repeating tris -carboxylate-bridged dimer unit with each zinc centre tetrahedral [Zn-O (mean) 1.958(5) �, Zn-Zn 3.393(2) �]. The dimer is extended into a linear polymer chain by an O,O' bridge through the carboxy group of the fourth carboxylate ligand.


1984 ◽  
Vol 39 (7) ◽  
pp. 903-906 ◽  
Author(s):  
Horst Elias ◽  
Rüdiger Grewe ◽  
Dirk-Detlev Klaehn ◽  
Helmut Paulus

Under mild conditions nickel(II) nitrate reacts with the macrocyclic N4 ligand TMBC ( = 1,4 ,8,11-tetramethyl-1,4,8,11-tetraazadibenzo[b,i]cyclotetradecane) to form the light blue-green complex Ni (TMBC) (NO3)2. A three-dimensional X-ray diffraction study shows that the complex crystallizes in the monoclinic space group P21/c with a = 896.1(3) pm, b = 2059.9(7) pm , c = 1298.6(6) pm, β = 91.37(1)° and Z = 4. The nickel is six-coordinate. The distorted octahedral N4O2 arrangement of donor atoms around the nickel is formed by the tetradentate N4 macrocycle TMBC in an unexpected folded form and by a nitrate ion as a bidentate ligand occupying two depositions. The structure could be refined to the final R-value of 0.045 only by assuming disorder for the second, noncoordinated nitrate ion.


1989 ◽  
Vol 44 (12) ◽  
pp. 1503-1508 ◽  
Author(s):  
Hubert Schmidbaur ◽  
Gabriele Weidenhiller ◽  
Aref A. M. Aly ◽  
Oliver Steigelmann ◽  
Gerhard Müller

Gold(I) complexes with secondary phosphines R2PH (la—d) of the type R2PH · AuCl (2a—d) have been obtained in good yield from reactions of (carbonyl)chlorogold(I) and the corresponding ligand in diethylether. Both compounds 2a, b bearing aromatic substituents with R = 2,4,6-trimethylphenyl (mesityl) and 2-methylphenyl (o-tolyl), and compounds 2c, d with the bulky alkyl substituents R = t-butyl and R = cyclohexyl, resp., are air-stable crystalline solids. — The coordination compounds have been characterized by NMR and IR data, and — in the cases of 2b and 2c — by single crystal X-ray diffraction studies. Crystals of these two compounds are both monoclinic, space group P21/c with four formula units (Z = 4). The analysis shows independent monomers for compound 2c with no intermolecular Au···Au contacts. Molecules of 2b are arranged in centrosymmetrical dimers (head to tail) with an Au···Au distance of 3.56 Å and a dihedral angle P—Au—Au′—P′ of 180°. (This structural study is as yet incomplete and suffers from an unsatisfactory data set for 2b.) It appears that intermolecular contacts are largely controlled by steric effects.


2015 ◽  
Vol 1088 ◽  
pp. 305-308
Author(s):  
Hui Duan Li

The construction, crystal structure and properties and potential application of metal imidazoledicarboxylate frameworks have currently attracted considerable attention. A novel open-framework Lanthanide imidazoledicarboxylate, [Tb (HpyimdC)(C2O4)0.5(H2O)]·(H2O)3(compound 1), was constructed from 2-(pyridine-3-yl)-1H-4,5-imidazoledicarboxylate (H3PyImdc) and Oxalate coordinated with lanthanide under solvothermal conditions. Single-crystal X-ray diffraction analysis reveals that compound 1 crystallized in the monoclinic space groupC2/c(No. 15). Oxalate chelated with Tb to form a one-dimensional zigzag chain, H3pyimdc with selective nitrogen−oxygen chelating site, constructed these chains into metal organic frameworks featuring extra-large channels deposited by guest molecules. Further characterizations for compound 1 have been performed, including X-ray powder diffraction, IR Spectrum and elemental analysis. Synthesis, crystal structure and structural characterizations for 1 were reported in this paper.


2020 ◽  
Vol 58 (5) ◽  
pp. 549-562
Author(s):  
Anatoly V. Kasatkin ◽  
Fabrizio Nestola ◽  
Radek Škoda ◽  
Nikita V. Chukanov ◽  
Atali A. Agakhanov ◽  
...  

ABSTRACT Hingganite-(Nd), ideally Nd2□Be2Si2O8(OH)2, is a new gadolinite group, gadolinite supergroup mineral discovered at Zagi Mountain, near Kafoor Dheri, about 4 km S of Warsak and 30 km NW of Peshawar, Khyber Pakhtunkhwa Province, Pakistan. The new mineral forms zones measuring up to 1 × 1 mm2 in loose prismatic crystals up to 0.7 cm long, where it is intergrown with hingganite-(Y). Other associated minerals include aegirine, microcline, fergusonite-(Y), and zircon. Hingganite-(Nd) is dark greenish-brown, transparent, has vitreous luster and a white streak. It is brittle and has a conchoidal fracture. No cleavage or parting are observed. Mohs hardness is 5½–6. Dcalc. = 4.690 g/cm3. Hingganite-(Nd) is non-pleochroic, optically biaxial (+), α = 1.746(5), β = 1.766(5), γ = 1.792(6) (589 nm). 2Vmeas. = 80(7)°; 2Vcalc. = 84°. Dispersion of optical axes was not observed. The average chemical composition of hingganite-(Nd) is as follows (wt.%; electron microprobe, BeO, B2O3, and Lu2O3 content measured by LA-ICP-MS; H2O calculated by stoichiometry): BeO 9.64, CaO 0.45, MnO 0.10, FeO 3.03, B2O3 0.42, Y2O3 8.75, La2O3 1.63, Ce2O3 12.89, Pr2O3 3.09, Nd2O3 16.90, Sm2O3 5.97, Eu2O3 1.08, Gd2O3 5.15, Tb2O3 0.50, Dy2O3 2.50, Ho2O3 0.33, Er2O3 0.84, Tm2O3 0.10, Yb2O3 0.44, Lu2O3 0.04, ThO2 0.13, SiO2 23.55, H2O 2.72, total 100.25. The empirical formula calculated on the basis of 2 Si apfu is (Nd0.513Ce0.401Y0.395Sm0.175Gd0.145Pr0.096Dy0.068La0.051Ca0.041Eu0.031Er0.022Tb0.014Yb0.011Ho0.009Tm0.003Th0.003Lu0.001)Σ1.979(□0.778Fe2+0.215Mn0.007)Σ1.000(Be1.967B0.062)Σ2.029Si2O8.46(OH)1.54. Hingganite-(Nd) is monoclinic, space group P21/c with a = 4.77193(15), b = 7.6422(2), c = 9.9299(2) Å, β = 89.851(2)°, V = 362.123(14) Å3, and Z = 2. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 6.105 (95) (011), 4.959 (56) (002), 4.773 (100) (100), 3.462 (58) (102), 3.122 , 3.028 (61) (013), 2.864 (87) (121), 2.573 (89) (113). The crystal structure of hingganite-(Nd) was refined from single-crystal X-ray diffraction data to R = 0.034 for 2007 unique reflections with I > 2σ(I). The new mineral is named as an analogue of hingganite-(Y), hingganite-(Yb), and hingganite-(Ce), but with Nd dominant among the rare earth elements.


1993 ◽  
Vol 58 (12) ◽  
pp. 2924-2935 ◽  
Author(s):  
Jane H. Jones ◽  
Bohumil Štíbr ◽  
John D. Kennedy ◽  
Mark Thornton-Pett

Thermolysis of [8,8-(PMe2Ph)2-nido-8,7-PtCB9H11] in boiling toluene solution results in an elimination of the platinum centre and cluster closure to give the ten-vertex closo species [6-(PMe2Ph)-closo-1-CB9H9] in 85% yield as a colourles air stable solid. The product is characterized by NMR spectroscopy and single-crystal X-ray diffraction analysis. Crystals (from hexane-dichloromethane) are monoclinic, space group P21/c, with a = 903.20(9), b = 1 481.86(11), c = 2 320.0(2) pm, β = 97.860(7)° and Z = 8, and the structure has been refined to R(Rw) = 0.045(0.051) for 3 281 observed reflections with Fo > 2.0σ(Fo). The clean high-yield elimination of a metal centre from a polyhedral metallaborane or metallaheteroborane species is very rare.


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1101
Author(s):  
Anirban Karmakar ◽  
Anup Paul ◽  
Elia Pantanetti Sabatini ◽  
M. Fátima C. Guedes da Silva ◽  
Armando J. L. Pombeiro

The new coordination polymers (CPs) [Zn(μ-1κO1:1κO2-L)(H2O)2]n·n(H2O) (1) and [Cd(μ4-1κO1O2:2κN:3,4κO3-L)(H2O)]n·n(H2O) (2) are reported, being prepared by the solvothermal reactions of 5-{(pyren-4-ylmethyl)amino}isophthalic acid (H2L) with Zn(NO3)2.6H2O or Cd(NO3)2.4H2O, respectively. They were synthesized in a basic ethanolic medium or a DMF:H2O mixture, respectively. These compounds were characterized by single-crystal X-ray diffraction, FTIR spectroscopy, thermogravimetric and elemental analysis. The single-crystal X-ray diffraction analysis revealed that compound 1 is a one dimensional linear coordination polymer, whereas 2 presents a two dimensional network. In both compounds, the coordinating ligand (L2−) is twisted due to the rotation of the pyrene ring around the CH2-NH bond. In compound 1, the Zn(II) metal ion has a tetrahedral geometry, whereas, in 2, the dinuclear [Cd2(COO)2] moiety acts as a secondary building unit and the Cd(II) ion possesses a distorted octahedral geometry. Recently, several CPs have been explored for the cyanosilylation reaction under conventional conditions, but microwave-assisted cyanosilylation of aldehydes catalyzed by CPs has not yet been well studied. Thus, we have tested the solvent-free microwave-assisted cyanosilylation reactions of different aldehydes, with trimethylsilyl cyanide, using our synthesized compounds, which behave as highly active heterogeneous catalysts. The coordination polymer 1 is more effective than 2, conceivably due to the higher Lewis acidity of the Zn(II) than the Cd(II) center and to a higher accessibility of the metal centers in the former framework. We have also checked the heterogeneity and recyclability of these coordination polymers, showing that they remain active at least after four recyclings.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Michael Zoller ◽  
Hubert Huppertz

AbstractThe rare earth oxoborates REB5O8(OH)2 (RE = Ho, Er, Tm) were synthesized in a Walker-type multianvil apparatus at a pressure of 2.5 GPa and a temperature of 673 K. Single-crystal X-ray diffraction data provided the basis for the structure solution and refinement. The compounds crystallize in the monoclinic space group C2 (no. 5) and are composed of a layer-like structure containing dreier and sechser rings of corner sharing [BO4]5− tetrahedra. The rare earth metal cations are coordinated between two adjacent sechser rings. Further characterization was performed utilizing IR spectroscopy.


1995 ◽  
Vol 50 (7) ◽  
pp. 1025-1029 ◽  
Author(s):  
J. Baurmeister ◽  
A. Franken ◽  
W. Preetz

By reaction of [N(C4H9 )4]2 [B6H6] with iodomethyl-trimethylsilane in acetonitrile a solution with trimethylsilylm ethyl-closo-hexaborate(1-)anions, [B6H6 (CH2Si(CH3)3)]-, is formed. The crystal structure of [P(C6H5 )4][B6H6(CH2Si(CH3)3)] has been determined by single crystal X-ray diffraction analysis; monoclinic, space group P21/n with a = 16.140(2), b = 11.646(8), c = 16.731(3) Å, β 109.664(11)°. The 11B NMR spectrum reveals features of a mono hetero substituted octahedral B6 cage. The 13C NMR spectrum exhibits a quartet at +0.18 ppm with 1J(C,H) = 118 Hz for the three methyl groups and a weak multiplet at -0.65 ppm for the methylene bridge due to quadrupole coupling with the boron atoms. In the 29Si NMR spectrum a decet at +2.25 ppm with 2J(C,H ) = 6.9 Hz is observed. The B -C stretching vibration is observed at 1155 cm-1 in the IR and Raman spectrum.


2020 ◽  
Vol 235 (8-9) ◽  
pp. 275-290
Author(s):  
Michael Schwarz ◽  
Pirmin Stüble ◽  
Katharina Köhler ◽  
Caroline Röhr

AbstractFour new mixed-valent chain alkali metal (A) sulfido ferrates of the general structure family ${A}_{1+x}\left[{\text{Fe}}_{x}^{\text{II}}{\text{Fe}}_{1-x}^{\text{III}}{\text{S}}_{2}\right]$ were synthesized in the form of tiny green-metallic needles from nearly stoichiometric melts reacting elemental potassium with natural pyrite (A = K) or previously prepared Rb2S/Cs2S2 with elemental iron and sulfur (A = Rb/Cs). The crystal structures of the compounds were determined by means of single crystal X-ray diffraction: In the (3+1)D modulated structure of K7.15[FeS2]4 (space group Ccce(00σ3)0s0, a = 1363.87(5), b = 2487.23(13), c = 583.47(3) pm, q = 0,0,0.444, R1 = 0.055/0.148, x = 0.787), a position modulation of the two crystallographically different undulated ${}_{\infty }{}^{1}\left[{\text{FeS}}_{4/2}\right]$ tetrahedra chains and the surrounding K cations is associated with an occupation modulation of one of the three potassium sites. In the case of the new monoclinic rubidium ferrate Rb4[FeS2]3 (x = $\frac{1}{3}$; space group P21/c, a = 1640.49(12), b = 1191.94(9), c = 743.33(6) pm, β = 94.759(4)°, Z = 4, R1 = 0.1184) the undulation of the tetrahedra chain is commensurate, the repetition unit consists of six tetrahedra. In the second new Rb ferrate, Rb7[FeS2]5 (x = 0.4; monoclinic, space group C2/c, K7[FeS2]5-type; a = 2833.9(2), b = 1197.36(9), c = 744.63(6) pm, β = 103.233(4)°, Z = 4, R1 = 0.1474) and its isotypic mixed Rb/Cs-analog Rb3.6Cs3.4[FeS2]5 (a = 2843.57(5), b = 1226.47(2), c = 759.890(10) pm, β = 103.7170(9)°, R1 = 0.0376) the chain buckling leads to a further increased repetition unit of 10 tetrahedra. For all mixed-valent ferrates, the Fe–S bond lengths continuously increase with the amount (x) of Fe(II). The buckling of the chains is controlled through the local coordination of the S atoms by the variable number of A cations of different sizes.


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