The New Vanadoborate-supported Hexanuclear Zinc Complex [Zn(teta)]6[(VO)12O6B18O36(OH)6](H2O) · 8H2O

2011 ◽  
Vol 66 (2) ◽  
pp. 115-118
Author(s):  
Xing Liu ◽  
Jian Zhou

The new vanadoborate-supported zinc complex [Zn(teta)]6[(VO)12O6B18O36(OH)6](H2O) ・8H2O (1, teta = triethylenetetramine) was synthesized hydrothermally and characterized by elemental and thermogravimetric analysis, and IR and UV/Vis spectroscopy. Complex 1 crystallizes in the trigonal system in space group R3̄ and consists of the neutral [Zn(teta)]6[(VO)12O6B18O36(OH)6](H2O) cage aggregate that is built up from a [(VO)12O6B18O36(OH)6]12− cluster decorated with six [Zn(teta)]2+ complex groups, and a water molecule occupying the center of the cluster cage.

2012 ◽  
Vol 67 (2) ◽  
pp. 127-22
Author(s):  
Anna J. Lehner ◽  
Korina Kraut ◽  
Caroline Röhr

Mixed sulfido/oxidomolybdate anions [MoOxS4−x]2− (x = 1, 2, 3) have been prepared by passing H2S gas through a solution of oxidomolybdates. The alkali salts of K+, Rb+, Cs+, and NH+4 precipitate as crystalline salts from these solutions depending on the pH, the polarity of the solvent, the educt concentrations and the temperature. Their structures have been determined by means of X-ray single-crystal diffraction data. All trisulfidomolybdates A2[MoOS3] (A = NH4/K/Rb/Cs) are isotypic with the tetrasulfido salts, exhibiting the β -K2[SO4] type (orthorhombic, space group Pnma, Z = 4; for A = Rb: a = 940.62(4), b = 713.32(4), c = 1164.56(5) pm, R1 = 0.0281). In contrast, the disulfidomolybdates exhibit a rich crystal chemistry, forming three different structure types depending on the preparation conditions and the size of the A cation: All four cations form salts crystallizing with the (NH4)2[WO2S2] structure type (monoclinic, space group C2/c, Z = 4, for A = Rb: a = 1144.32(11), b = 732.60(4), c = 978.99(10) pm, β = 120.324(7)°, R1 = 0.0274). For the three alkali metal cations a second polymorph with a new structure type (monoclinic, space group P21/c, Z = 4) is observed in addition (for A = Rb: a = 674.83(2), b = 852.98(3), c = 1383.10(9) pm, β = 115.19(1)°, R1 = 0.0216). The cesium salt also crystallizes with a third modification of another new structure type (orthorhombic, space group Pbcn, Z = 4, a = 915.30(6), b = 777.27(7), c = 1120.02(7) pm, R1 = 0.0350). Only for K, an anhydrous monosulfidomolybdate could be obtained (K2[MoO4] structure type, monoclinic, space group C2/m, Z = 4, a = 1288.7(3), b = 615.7(2), c = 762.2(1) pm, β = 109.59(1)°, R1 = 0.0736). The intramolecular chemical bonding in the molybdate anions is discussed and compared with the respective vanadates. Hereby aspects like bond lengths, bond strengths and force constants derived from Raman spectroscopy, are taken into account. Especially for the polymorphic disulfido salts, in-depth analyses of the local coordination numbers and the packing of the ions are presented. The gradual bathochromic shift of the crystal color with increasing S content and increasing size of the counter cations A and molar volumes (for the polymorphic forms), respectively, is in accordance with the increase of the experimental (UV/Vis spectroscopy) and calculated (FP-LAPW band structure theory) band gaps.


Author(s):  
G. Reck ◽  
B. Schulz ◽  
A. Zschunke ◽  
O. Tietze ◽  
J. Haferkorn

AbstractN,N′-ethylene-bis-(tetronic-acid-3-formiminato)-copper(II)/K1 crystallizes in space groupN,N′-ethylene-bis-(tetronic-acid-3-formiminato)-nikkel(II)/K2 crystallizes in space groupN,N′-ethylene-bis-(1,5,5-trimethyltetramic-acid-3-formiminato)-copper(II)/K3 crystallizes in space groupIn K1 and K3 copper is coordinated by two nitrogen and two oxygen atoms of the ligand molecule as well as by one water molecule on top of a tetragonal pyramid. In K2 two water molecules are included in the complex formation. These and two nitrogen as well as two oxygen ligand atoms form a nearly regular octahedron.


2017 ◽  
Vol 8 ◽  
pp. 1191-1204 ◽  
Author(s):  
Rasha K Al-Shewiki ◽  
Carola Mende ◽  
Roy Buschbeck ◽  
Pablo F Siles ◽  
Oliver G Schmidt ◽  
...  

Subsequent treatment of H2TPP(CO2H)4 (tetra(p-carboxylic acid phenyl)porphyrin, 1) with an excess of oxalyl chloride and HNR2 afforded H2TPP(C(O)NR2)4 (R = Me, 2; iPr, 3) with yields exceeding 80%. The porphyrins 2 and 3 could be converted to the corresponding metalloporphyrins MTPP(C(O)NR2)4 (R = Me/iPr for M = Zn (2a, 3a); Cu (2b, 3b); Ni (2c, 3c); Co (2d, 3d)) by the addition of 3 equiv of anhydrous MCl2 (M = Zn, Cu, Ni, Co) to dimethylformamide solutions of 2 and 3 at elevated temperatures. Metalloporphyrins 2a–d and 3a–d were obtained in yields exceeding 60% and have been, as well as 2 and 3, characterized by elemental analysis, electrospray ionization mass spectrometry (ESIMS) and IR and UV–vis spectroscopy. Porphyrins 2, 2a–d and 3, 3a–d are not suitable for organic molecular beam deposition (OMBD), which is attributed to their comparatively low thermal stability as determined by thermogravimetric analysis (TG) of selected representatives.


1986 ◽  
Vol 41 (12) ◽  
pp. 1495-1500 ◽  
Author(s):  
Christian Robl ◽  
Armin Weiss

AbstractBaC6X2O4 · 3H2O (X = Cl, Br) crystallizes in the orthorhombic space group Cmca. 4 of the 8 oxygen atoms around Ba2+ belong to two different dianions, chelating Ba2+. In this way 1-dimensional corrugated chains are formed, interlinked by two oxygen atoms of neighbouring chains, thus forming layers. This interconnection is of polar character within a layer. The in­terlinking oxygen atoms have one carbon- and two Ba2+ neighbours. CN 8 is completed by two water molecules. The latter and a further water molecule situated between the layers may be removed reversibly in a topochemical reaction without destruction of the structure.


2001 ◽  
Vol 56 (10) ◽  
pp. 1025-1034 ◽  
Author(s):  
Markus Ströbele ◽  
H.-Jtirgen Meyer

The title compounds were prepared through reactions of Li2Nb6Cl16 with the corresponding crown ethers in acetone. All three compounds were obtained as dark brown crystals. Their structures were solved with the means of single-crystal X-ray diffraction.[Li(12-crown-4)2][Li(12-crown-4)(OH2)]2[Nb6Cl18]: space group P21/n, Z =2, a = 1320.4(1), b = 1879.1(1), c = 1321.7(1) pm, ß = 92.515(6)°, R1 = 0.0297 (I>2σ(I)). The crystal structure contains Li+ sandwiched by two 12-crown-4-ethers plus Li+ coordinated by one 12-crown-4- ether and one water molecule.[Li(15-crown-5)2(OH2)]3[Nb6Cl18]: space group R3̅, Z = 3, a = b = 2081.7(1), c = 1991.7(1) pm, R1 = 0.0395 (I > 2σ(I)). In the crystal structure Li+ and one water molecule are sandwiched by two 15-crown-5-ethers.[(18-crown-6)2(O2H5)]3[Nb6Cl18]: space group P1̅, Z = 1 ,a = 1405.1(1), b = 1461.1(2), c = 1492.2(2) pm; α = 98.80(1)°, ß = 98.15(1)°, γ = 97.41(1)°, R1 = 0.0538 (I > 2σ(I)). H5O2+ was found in the structure refinement sandwiched between two 18-crown-6-ethers.All compounds reported contain [Nb6Cl18] clusters with Nb-Nb distances between 299 and 301 pm. The paramagnetic behaviour expected for [Nb6Cl18]3- in all three compounds was confirmed by magnetic measurements.


1994 ◽  
Vol 47 (10) ◽  
pp. 1885 ◽  
Author(s):  
NF Curtis ◽  
AR Davis ◽  
FWB Einstein

Intermediate products have been isolated from the reaction of (4,4,9,9-tetramethyl-5,8-diazadodecane-2,11-dione dihydrazone )nickel(II) perchlorate with butane-2,3-dione which finally yields the macrocyclic product (3,4,7,9,9,14,14,16-octamethyl-1,2,5,6,10,13-hexaazacyclohexa-deca-2,4,6,16-tetraene)nickel(II) perchlorate , [Ni( omht )] (ClO4)2. An initial violet product is assigned a structure with the macrocyclic ligand 3-acetyl-3,6,8,8,13,13,15-heptamethyl-1,2,4,5,9,12-hexaazacyclopentadeca-5,15-diene. In water this converts into an equilibrium mixture of the tautomeric cations blue cis-aqua(3,4,7,9,9,14,14,16-octamethyl-1,2,5,6,10,13-hexaazacyclohexadeca-1(16),4,6-trien-3-ol)nickel(II), cis-[Ni(L2)(H2O)]2+, and orange (3,6,8,- 8,13,13-hexamethyl-4,5,9,12-tetraazahexadeca-3,5-diene-2,15-dione 15-hydrazone)nickel(II), [Ni(L3)]2+. The rates at 25°C of the forward and reverse reactions of this tautomerism, and of the slower conversion of the equilibrium mixture to [Ni( omht )](ClO4)2, are reported. The structure of cis -[Ni(L2)(H2O)](ClO4)2.3H2O has been determined by X-ray diffractometry (monoclinic, space group P21/n, a 9.694(8), b 19.218(14), c 16.652(9) Ǻ, β 94.88(1)°, R 0.079 for 3254 reflections). This has NiII in octahedral coordination by secondary amine nitrogen atoms 10 and 13, hydrazone nitrogen atoms 1 and 6, and the carbinolamine oxygen substituent at position 3 of the pentadentate macrocyclic ligand L2, with a water molecule coordinated cis to the hydroxy group. Compounds of the tautomeric cations [Ni(L2)]2+ and [Ni(L3)]2+ with coordinated thiocyanate, azide, nitrite, oxalate and acetate are described.


2014 ◽  
Vol 70 (a1) ◽  
pp. C656-C656
Author(s):  
Hamza Kherfi ◽  
Malika Hamadène ◽  
Achoura Guehria-Laidoudi ◽  
Slimane Dahaoui ◽  
Claude Lecomte

We report here two bimetallic oxalate isomers with the same chemical formula [RbCr(C2O4)2(H2O)2], which have been synthesized respectively by a slow evaporation method at room temperature (compound I) [1], and under hydrothermal conditions (compound II) [2] with the same starting salts. Their structures show a several discrepancies, due probably to the synthetic conditions. Indeed, the compound I crystallizes in space group C2/m with the Cr, Rb atoms and one oxygen from water molecule lying on special positions. Moreover, the unique oxalate ligand forms a bridge between metal centers. The Cr atom is coordinated to 2 bidentate-chelating oxalates and 2 aqua ligands in a trans-conformation and any water molecule has been found around the 8-coordinated Rb atom, leading to a layered structure consists of alternating Rb and Cr polyhedra connected via the unique organic ligand. Whereas, the compound II crystallizes in space group P21/n, with all atoms located on general positions. Furthermore, two independent oxalato ligands exhibit different configurations, which one is pentadentate and the other is hexadentate with two different chelating modes. The very slightly distorted Cr octahedra consists of 2 bidentate-chelating oxalato ligands and 2 water molecules in a cis-conformation, while the alkali metal is surrounded by seven O atoms from oxalate groups, completed with two H2O molecules which are bridging the Cr and Rb polyhedra by one common edge. This results in the formation of three different chains of alternating edge- and vertex-shared polyhedra through oxalates groups and aqua ligands, running along the three space directions to build a three dimensional framework. These two compounds can be considered as supramolecular isomers [3].


1996 ◽  
Vol 51 (10) ◽  
pp. 1464-1468 ◽  
Author(s):  
Walter Frank ◽  
Guido J. Reiß

Tris(guanidinium) hexachlororhodate(III) monohydrate, [C(NH2)3]3[RhCl6] · H2O (1 ) has been obtained by the reaction of rhodium(III) chloride with guanidine hydrochloride in hydrochloric acid solution. 1 crystallizes in the triclinic space group P1̅ (a = 7.6013(9) Å, b = 8.6912(10) Å, c = 15.956(2) Å, α = 93.177(10)°, β = 101.691(10)°, γ = 113.995(9)°, V = 931.8(2), Z = 2). Two crystallographically independent hexachlororhodate ions, three crystallographically independent guanidinium ions and one water molecule are linked by a complex framework of hydrogen bonds.


1994 ◽  
Vol 49 (9) ◽  
pp. 1272-1276 ◽  
Author(s):  
Bernward Engelen

The crystal structure of MnSO3H2O , space group P21/n, Z = 4. Dx = 2.842(2) g · cm-3, a = 4.843(3), b = 12.807(6), c = 5.762(4) Å, β = 90.39(4)° has been determined. MnSO3·H2O crystallizes in a hitherto unknown structure type, which is closely related to that of orthorhombic MnSeO3· D2O. Coordination of Mn is octahedral involving O atom s from one water moleculeo and four different sulfite ions. The Mn-O distances range from 2.136(3) to 2.285(3)Å . The S-O distances are 1.552(3), 1.556(3) and 1.482(3)!Å. The MnO6 octahedra form layers parallel (010) by sharing four equatorial vertices. The layers are connected by weak hydrogen bonds and shifted laterally by 0.7 Å from the arrangement with m symmetry, found in MnSeO3·D2O. Due to this shift, the water molecule is asymmetrically bonded, as shown by both the O-H···O distances (2.967(4)-3.834(5)Å) and the OD stretching modes (2554 and 2576 cm-1) of partly deuterated samples


2012 ◽  
Vol 68 (4) ◽  
pp. o1184-o1184 ◽  
Author(s):  
Tao Yu ◽  
Yimin Hu

The crystal structure of the title compound, C26H21NO3·0.25H2O, reveals one stereogenic centre in the molecule. Nevertheless, due to the observed centrosymmetric space group, both enantiomers are present in the crystal packing. The water molecule of crystallisation is located on a crystallographic inversion center. The molecule contains one five-membered ring (A) and three six-membered rings (benzyl ringB, benzylidene ringCand formylbenzyl ringD). All four rings are not coplanar: the dihedral angles between ringsAandB,AandC, andAandDare 70.35 (9), 33.8 (1) and 60.30 (9)°, respectively. In the crystal, pairs of weak C—H...O interactions lead to the formation of centrosymmetric dimers. Additional C—H...O interactions link the dimers into chains along [011].


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