Crystal Chemistry of the Saccharinato Complexes of Trivalent Lanthanides and Yttrium

Saccharinate complexes of the fourteen trivalent lanthanide cations and Y^III were prepared by reaction between the respective lanthanide carbonates and saccharin in aqueous solution. Their crystal structures were determined by single crystal X‐ray diffractometry. They represent three different structural types. The first family, of composition [Ln(sac)(H₂O)₈](sac)₂�H₂O (sac = anion of saccharin; Ln = La, Ce, Pr, Nd.Sm, Eu), belongs to the monoclinic space group P2₁/c with Z = 4 and the Ln^III cation is in a tricapped trigonal prismatic environment with nine‐fold oxygen coordination. The second group of composition [Ln(sac)₂(H₂O)₆]‐(sac)(Hsac)�4H₂O with Ln = Gd, Dy, Ho, Er, Yb, Lu, and Y, pertains to the triclinic P1¯‐ space group, with Z = 2 and constitutes a new example of complexes containing simultaneously saccharin and its anion in the lattice. The Tm^III and Tb^III compounds, which are also triclinic (space group P1¯‐ and Z = 2) present two closely related structures conformed by three and two [Ln(sac)(H₂O)₇]²⁺ crystallographically independent complexes, respectively, with the [Tm(sac)(H₂O)₇]₃(sac)₆�9H₂O and [Tb(sac)(H₂O)₇]2(sac)₄�6H₂O composition. For all the heavier lanthanides (Gd‐Lu) and yttrium the cation presents eight‐fold oxygen coordination, with the ligands at the corners of a slightly distorted square Archimedean antiprism.     

Saccharin complexes of zinc(II) with phenanthroline and 2,9-dimethyl-1,10-phenanthroline: synthesis and characterization

The saccharinato complexes [Zn(phen)₂(sac)(H₂O)]sac (1) and [Zn(sac)(dmp)(H₂O)](sac) (2), where phen = 1,10-phenanthroline, dmp = 2,9-dimethyl-1,10-phenanthroline, and sac =saccharinato ion/ligand, were synthesized by the reaction of [Zn(sac)₂(H₂O)₄] · 2H₂O with ligands and have been characterized by elemental analysis, IR, and ¹H NMR spectroscopies. Conductivity of complexes was measured in DMSO. Compound 1 is characterized by single crystal X-ray diffraction and compared with some isomorphous zinc-saccharinate complexes reported previously. Complex 1 crystallizes in the triclinic system, space group P 1 , with Z = 2, and consists of alternating slightly distorted octahedral [Zn(phen)₂(sac)(H₂O)]⁺ and noncoordinated saccharinate. The zinc bound aqua is hydrogen bonded to an oxygen of carbonyl in the saccharinate ligand and the SO₂ group in the saccharinate counter-ion from an adjacent molecule. Intermolecular and intramolecular hydrogen bonds and C–H ··· O and C–H ··· N short contacts lead to a 3-D network.     

The dangers of using KBr,KI and CaI2 as mulling agents during the preparation of infrared discs of complexes

Tribochemical reactions of KBr, KI and CaI₂ with [Cu(L)Cl₂(EtOH)_3/2(H₂O)]1/2H₂O (L = formylhydrazine) give novel Cu^I and Cu^II complexes, which have been characterized by elemental analyses, spectral (i.r., u.v.–vis., ¹H-n.m.r.) and magnetic measurements. The i.r. spectra indicate that (L) behaves in a monodentate manner, coordinating via the azomethine nitrogen (C-N) group in the Cu^II complexes, but behaving as a bidentate ligand, via the carbonyl oxygen and NH₂ groups in the Cu^I complexes. KI and CaI₂ react with [Cu(L)Cl₂(EtOH)_3/2(H₂O)]-1/2H₂O in the solid state, accompanied by a colour change, substitution of the chloride by iodide ions, and reduction of Cu^II to Cu^I to give complexes with formulae [Cu(L)I(EtOH)_1/2] and [Cu_1.7(L)I_1.7(EtOH)_1/2]. On the other hand, the tribochemical reaction of KBr with [Cu(L)Cl₂(EtOH)_3/2(H₂O)]1/2H₂O is accompanied by a colour change; substitution of the chloride by bromide ions, but without reduction of Cu^II and yields a complex of formula [Cu(L)₂Br₂(EtOH)(H₂O)]1/2EtOH. The spectral and magnetic results suggest a distorted octahedral geometry for the Cu^II complexes while a tetrahedral geometry around the Cu^I ion. The non-stoichiometric structure of [Cu_1.7(L)I_1.7(EtOH)_1/2] is discussed.     

Metal complexes with N-(trifluoromethylbenzyl)iminodiacetate chelators (x-3F ligands). Part I. Copper(II) chelates of p-3F,m-3F,and o-3F with or without imidazole-like ligands

Eight Cu(II) complexes with N-(p-, m- or o-trifluoromethylbenzyl)iminodiacetate chelators (x-3F ligands) have been synthesized to promote C–F/H interligand interactions involving the F₃C-group: {[Cu(μ₂-p-3F)(H₂O)]·3H₂O]}_n (1), [Cu(m-3F)(H₂O)₂] (2), [Cu(p-3F)(Him)(H₂O)] (3), [Cu(m-3F)(Him)(H₂O)] (4), [Cu(o-3F)(Him)(H₂O)] (5), [Cu₂(p-3F)₂(H5Meim)₂(H₂O)₂] (6), [Cu(m-3F)(H5Meim)(H₂O)] (7), and [Cu(o-3F)(H5Meim)(H₂O)] (8) [Him and H5Meim = imidazole and the “remote” tautomer 5-methylimidazole, respectively]. The compounds were studied by single-crystal X-ray diffraction, FT-IR, electronic spectra and coupled thermogravimetric + FT-IR methods. The conformation of the iminodiacetate chelating moiety (IDA group) is fac-NO + O(apical) in 1 and mer-NO₂ in 2–8. The fac-IDA conformation observed in 1 is related to its polymeric structure and the coordination of a O’-carboxylate donor, from an adjacent complex unit, trans to the Cu–N(IDA) bond. The mer-IDA conformation in 2 is in agreement with similar compounds with an aqua ligand trans to the corresponding Cu–N(IDA) bond. As expected, the ternary complexes 3–8 feature a mer-IDA conformation. Some of the studied complexes exhibit disorder in the –CF₃ group and C–H?F interligand interactions along with conventional N–H?O and O–H?O interactions. The thermal decomposition of all studied compounds under air flow produces variable amounts of trifluorotoluene.     

Synthesis and characterization of mixed-ligand copper(II) saccharinate complexes containing tridentate NNS Schiff bases. X-ray crystallographic analysis of the free ligands and one complex

Four new Schiff bases containing N and S heteroatoms (HL1–HL4) have been prepared and characterized, including determination of the X-ray crystal structures of HL1 and HL3. Spectroscopic evidence indicates that these Schiff bases behave as uninegatively charged tridentate NNS ligands in complexes of general formula [Cu(Ln)sac] (Ln is the anionic form of NNS, and sac represents saccharinate anion). Crystals of both HL1 and [Cu(L4)sac)(H₂O)]·Hsac crystallized in triclinic system with P $ \bar{1} $ space group, while HL3 crystallized in monoclinic system with P 2₁/c space group. [Cu(L4)sac)(H₂O)]·Hsac has a distorted square-pyramidal structure with a non-bonded saccharin molecule present in the outer coordination sphere. The tridentate NNS ligands are coordinated to Cu through pyridine nitrogen, azomethine nitrogen and thiolate sulfur atoms, while the fourth and fifth coordination positions are occupied by the N-bonded saccharinate anion and a water ligand, respectively.     

Structure and Magnetic Properties of Mononuclear Copper(II) Complexes with 2,2‐Bipyrimidine, 2,3‐Bis(2‐pyridyl)pyrazine,and 4‐Terpyridone Based Ligands

Four new complexes of [Cu(bpm)(ox)(H₂O)] ( 1 ), [Cu(tpd)(dca)(H₂O)] ( 2 ), [Cu(bppz)(N₃)₂] ( 3 ), and [Cu(bpm)₂(μ_1,3‐N₃)(N₃)] ( 4 ) (bpm = 2,2′‐bipyrimidine, bppz = 2,3‐bis(2‐pyridyl)pyrazine, tpd = 4‐terpyridone, dca = dicyanamide, ox = oxalate) have been prepared and characterized by X‐ray single‐crystal analysis and variable‐temperature magnetic measurements. Compounds 1–4 are essentially mononuclear Cu(II) complexes. However, in complex 1 , Cu(II) it was found that intermolecular hydrogen bonding through between H₂O and ox formed 1‐D chain structure. In complex 2 it was found that the hydrogen bonding between H₂O and tpd of the next molecule led to for a binuclear Cu(II) complex. In complex 3 , two nitrogen atoms, one of the pyridyl group of bppz and one of N₃^? ligands, are weakly coordinated to neighbor Cu(II) ion thus leading to formation of a 1‐D chain structure. In complex 4 , one nitrogen atom of terminated N₃^? is weakly coordinated to the neighbor Cu(II) site to form a 1‐D polymeric structure. The magnetic susceptibility measurements indicate that complex 1 and 4 exhibit a weak antiferromagnetic interaction whereas a ferromagnetic coupling has been established for complexes 2 and 3 .     

Crystal Structures and Raman Spectra of cis‐[SnCl4(H2O)2]·2H2O,cis‐[SnCl4(H2O)2]·3H2O, [Sn2Cl6(OH)2(H2O)2]·4H2O,and [HL][SnCl5(H2O)]·2.5H2O (L=3‐acetyl‐5‐benzyl‐1‐phenyl‐4, 5‐dihydro‐1, 2, 4‐triazine‐6‐one oxime,C18H18N4O2)

The complexes cis‐[SnCl₄(H₂O)₂]·2H₂O ( 1 ), [Sn₂Cl₆(OH)₂(H₂O)₂]·4H₂O ( 3 ), and [HL][SnCl₅(H₂O)]·2.5H₂O ( 4 ) were isolated from a CH₂Cl₂ solution of equimolar amounts of SnCl₄ and the ligand L (L=3‐acetyl‐5‐benzyl‐1‐phenyl‐4, 5‐dihydro‐1, 2, 4‐triazine‐6‐one oxime, C₁₈H₁₈N₄O₂) in the presence of moisture. 1 crystallizes in the monoclinic space group Cc with a = 2402.5(1) pm, b = 672.80(4) pm, c = 1162.93(6) pm, β = 93.787(6)° and Z = 8. 4 was found to crystallize monoclinic in the space group P2₁, with lattice parameters a = 967.38(5) pm, b = 1101.03(6) pm, c = 1258.11(6) pm, β = 98.826(6)° and Z = 2. The cell data for the reinvestigated structures are: [SnCl₄(H₂O)₂]·3H₂O ( 2 ): a = 1227.0(2) pm, b = 994.8(1) pm, c = 864.0(1) pm, β = 103.86(1)°, with space group C2/c and Z = 4; 3 : a = 961.54(16) pm, b = 646.29(7) pm, c = 1248.25(20) pm, β = 92.75(1)°, space group P2₁/c and Z = 4.     

Binary and Ternary Metal Complexes Derived from Cu Acetate with Some Sulfur-Containing Chemotherapeutic Agents

Two ternary complexes, [Cu₂(Pir)(Pen)(OH)(Ac)H₂O] and [Cu(Pir)(Cap)(Ac)] ½H₂O (where, Pen = D-penicillamine, Cap = captopril, and Pir = piroxicam) have been synthesized and characterized using elemental analyses, spectroscopic analyses (IR, UV-vis, MS), thermal analyses (TGA), conductance measurements, and magnetic measurements. The binary complexes, [Cu₂(Pen)(OH)₂(H₂O)₂] 4H₂O and [Cu(Cap)Ac] 3/2H₂O, have also been prepared and characterized by these techniques to facilitate the interpretation of the mixed ligand complexes. The results show that D-penicillamine can coordinate two copper atoms through amino nitrogen, and thiol sulfur after displacement of a hydrogen atom. At the same time, the ligand coordinates to the second copper atom through a carboxyl group after displacement of a hydrogen from the latter group. Captopril coordinates through thiol sulfur and carbonyl oxygen. Piroxicam coordinates as a neutral bidentate ligand in the keto form through carbonyl oxygen and pyridyl nitrogen. The magnetic moment measurements of complexes containing captopril indicate the reduction of Cu(II) to Cu(I) by the thiol group.     

Supramolecular Stuctures from Mononuclear,Binuclear and 2D Net of Copper(II) Complexes with 6‐Hydroxypicolinic Acid

First examples of transition metal complexes with HpicOH [Cu(picOH)₂(H₂O)₂] ( 1 ), [Cu(picO)(2,2′‐bpy)]·2H₂O ( 2 ), [Cu(picO)(4,4′‐bpy)_0.5(H₂O)]_n ( 3 ), and [Cu(picO)(bpe)_0.5(H₂O)]_n ( 4 ) (HpicOH = 6‐hydroxy‐picolinic acid; 2,2′‐bpy = 2,2′‐bipyridine; 4,4′‐bpy = 4,4′‐bipyridine; bpe = 1,2‐bis(4‐pyridyl)ethane) have been synthesized and characterized by single‐crystal X‐ray diffraction. The results show that HpicOH ligand can be in the enol or ketonic form, and adopts different coordination modes under different pH value of the reaction mixture. In complex 1 , HpicOH ligand is in the enol form and adopts a bidentate mode. While in complexes 2 – 4 , as the pH rises, HpicOH ligand becomes in the ketonic form and adopts a tridentate mode. The coordination modes in complexes 1 – 4 have not been reported before. Because of the introduction of the terminal ligands 2,2′‐bpy, complex 2 is of binuclear species; whereas in complexes 3 and 4 , picO ligands together with bridging ligands 4,4′‐bpy and bpe connect Cu^II ions to form 2D nets with (12³)₂(12)₃ topology.     

A One‐Dimensional Pyrazine Bridged Copper(II)‐Saccharinato Coordination Polymer

A one‐dimensional copper(II) complex {[Cu(sac)₂(μ‐pyz)(H₂O)]·H₂O}_n ( 1 ) (pyz = pyrazine, and sac = saccharinate) has been synthesized and characterized by elemental analysis, IR spectroscopy, thermal and single crystal X‐ray analyses. Complex 1 crystallizes in the triclinic space group . The [Cu(sac)₂(H₂O)] units are bridged by pyz leading to a one‐dimensional alternating chain in which the copper(II) ions exhibit a distorted square–pyramidal coordination of CuN₄O. The intradimer Cu···Cu distance is 6.881Å, while interdimer Cu···Cu distance is 7.066Å. The supramolecular interactions are mainly controlled by the sac anion and water molecules. The individual chains are linked by strong OW–H···O(sac) hydrogen bonds into a two‐dimensional layers, which are further arranged in a three‐dimensional supramolecular network by aromatic π(sac)···π(sac) stacking interactions and CH···π(pyz) interactions. Thermal analysis of complex 1 shows that the decompositions of the aqua, pyz and sac ligands are observed as distinct steps on the DTA and TG curves.     

Selten‐Erd‐Metall‐Koordinationspolymere: Synthesen und Kristallstrukturen von drei neuen Glutaraten, [Pr2(Glu)3(H2O)4] · 10,5H2O, [Pr(Glu)(H2O)2]Cl und [Er(Glu)(GluH)(H2O)2]

Rare‐Earth‐Metal Coordination Polymers: Syntheses and Crystal Structures of Three New Glutarates, [Pr₂(Glu)₃(H₂O)₄] · 10.5H₂O, [Pr(Glu)(H₂O)₂]Cl, and [Er(Glu)(GluH)(H₂O)₂] The new rare‐earth dicarboxylates [Pr₂(Glu)₃(H₂O)₄] · 10.5H₂O ( 1 ), [Pr(Glu)(H₂O)₂]Cl ( 2 ) and [Er(Glu)(GluH)(H₂O)₂] ( 3 ) were obtained from the reactions of glutaric acid with PrCl₃·6H₂O and Er(OH)₃, respectively. The crystal structures were determined by single‐crystal X‐ray diffraction. [Pr₂(Glu)₃(H₂O)₄] · 10,5H₂O crystallizes in the orthorhombic space group Pnma (no. 62) with a = 871.7(4), b = 3105.0(9), c = 1308.3(9) pm and Z = 4. The crystals of [Pr(Glu)(H₂O)₂]Cl are monoclinic (I2/a; no. 15) with a = 786.2(1), b = 1527.6(2) c = 801.2(1) pm, β = 99.78(1)° and Z = 4. [Er(Glu)(GluH)(H₂O)₂] crystallizes in the monoclinic space group P2₁/a (no. 14) with lattice parameters of a = 882.4(1), b = 1375.3(2), c = 1267.4(2) pm, β = 107.13(1)° and Z = 4. The rare‐earth cations have the coordination numbers 10 ( 1 ), 8 + 1 ( 2 ) and 9 ( 3 ). The individual polyhedra are connected to chains and further to sheets in 1 and 2 and to double chains in 3 . Only in the water‐rich compound 1 there are channels that contain crystal water molecules. It, therefore, has a considerably lower density than 2 and 3 .     

Syntheses,Crystal Structures,and Magnetic Properties of Three 1D Chain Metal–Nitroxide Complexes Bridged by ­Flexible Dicarboxylate Anions

Three new one‐dimensional (1D) chain metal–nitroxide complexes {[Cu(NIT4Py)₂(suc)(H₂O)] · 3H₂O}_n ( 1 ), {[Cd(NIT4Py)₂(suc)(H₂O)] · [Cd(NIT4Py)₂(suc)(H₂O)₂] · 3H₂O}_n ( 2 ), and {[Zn(NIT4Py)(glu)(H₂O)] · H₂O}_n ( 3 ) [NIT4Py = 2‐(4′‐pyridyl)‐4, 4, 5, 5‐tetramethylimidazoline‐1‐oxyl‐3‐oxide, suc = succinate anion and glu = glutarate anion] were synthesized and structurally characterized. Single‐crystal X‐ray analyses indicate that the three complexes crystallize in neutral 1D chains in which the metal‐nitroxide units are linked by flexible dicarboxylate anions. The succinate anions only adopt trans configuration in complexes 1 and 2 , whereas the glutarate anion has gauche/anti conformation in complex 3 . Magnetic measurements show that complex 1 exhibits weak antiferromagnetic interactions between the copper ions and the nitroxides.     

Spectroscopic studies and biological evaluation of some transition metal complexes of Schiff-base ligands derived from 5-arylazo-salicylaldehyde and thiosemicarbazide

Synthesis and spectroscopic characterization of Schiff-base complexes of Cu(II), Ni(II), and Mn(II) resulting from condensation of salicylaldehyde derivatives with thiosemicarbazide [PHBT = 1-(5-(2-phenyldiazenyl)-2-hydroxybenzylidene)thiosemicarbazide, CHBT = 1-(5-(2-(2-chlorophenyl)diazenyl)-2-hydroxybenzylidene)thiosemicarbazide, and MHBT = 1-(5-(2-p-tolyldiazenyl)-2-hydroxybenzylidene)thiosemicarbazide] are discussed. The solid complexes were confirmed by elemental analysis (CHN), molar conductance, and mass spectra. Important infrared (IR) spectral bands corresponding to the active groups in the three ligands, ¹H-NMR and UV-Vis spectra and thermogravimetric analysis were performed. The dehydration and decomposition of [Cu(PHBT)(H₂O)], [Ni(PHBT)(H₂O)] · 2H₂O, [Mn(PHBT)(H₂O)] · H₂O, [Cu(CHBT)(H₂O)], [Ni(CHBT)(H₂O)] · H₂O, [Mn(CHBT)(H₂O)] · H₂O, [Cu(MHBT)(H₂O)], [Ni(MHBT)(H₂O)] · 2H₂O, and [Mn(MHBT)(H₂O)] · 2H₂O complexes were studied. The ligands are tridentate forming chelates with 1 : 1 (metal : ligand) stoichiometry. The molar conductance measurements of the complexes in DMSO indicate non-electrolytes. The biological activities of the metal complexes have been studied against different gram positive and gram negative bacteria.     

The first tris(saccharinato) complexes. Syntheses, spectral, thermal and structural characterization of ApyH[Cu(N–sac)2(O–sac)(H2O)2] and ApyH[Zn(N–sac)3- (H2O)] (ApyH=2–aminopyridinium and sac=saccharinate)

The reaction of the Schiff base salicylideneaminopyridine with [M(sac)₂(H₂O)₄] · 2H₂O, where M is copper(II) or zinc(II), and sac is the saccharinate anion, results in the formation of the new tris(saccharinato) complexes ApyH[Cu(N-sac)₂ (O-sac)(H₂O)₂] (1) and ApyH[Zn(N-sac)₃(H₂O)] (2), which have been characterized by elemental analyses, magnetic measurements, FT-IR spectroscopy, thermal analysis and X-ray diffraction. The Schiff base did not coordinate to the metal ions, but decomposed during the reaction, forming a 2-aminopyridinium cation ApyH, which remained outside the coordination sphere as a counter ion. (1) and (2) are the first examples of mononuclear tris(saccharinato) complexes of copper(II) and zinc(II). Both complexes are isomorphous with the triclinic space group P-1, (1) consisting of an ApyH cation and a [Cu(sac)₃(H₂O)₂]^– anion in which the copper(II) ion has trigonal bipyramidal surroundings. The sac ligands in (1) exhibit unusual and non-equivalent coordination, behaving as ambidentate ligands. One of them coordinates to the metals through the carbonyl oxygen atom, while the other two sac ligands are bonded to the metals via the imino nitrogen atom. The zinc(II) ion in (2) is tetrahedrally coordinated by three N-donor sac ligands and an aqua ligand. The crystal structures of (1) and (2) are stabilized by intermolecular hydrogen bonds and aromatic – stacking interactions.     

COORDINATION COMPOUNDS OF NICKEL WITH TRITHIOCYANURIC ACID

Abstract

Nickel(II) complexes with a combination of trithiocyanuric acid and diamines or triamines of composition [Ni(aepa)(ttcH)(H₂O)], [Ni(dien)(ttcH)(H₂O)], [Ni(dpta)(ttcH)(H₂O)] H₂O, [Ni(phen)₂(ttcH)]H₂O, [Ni(phen)₃](ttcH)-5H₂O and [Ni(1,2-pn)₃](ttcH)-H₂O (aepa = N-(2-aminoethyl)-1,3-propanediamine,dien = diethylenetriamine,dpta = dipropylenetnamine, phen = 1,10-phenanthroline, 1,2-pn = 1,2-diaminopropane. ttcH₃ = trithiocyanuric acid) have been prepared. The compounds have been characterized by means of elemental analysis, IR and electronic spectroscopies and magnetochemical measurements. Selected complexes were studied by thermal analysis. The compounds can be characterized as distorted octahedral Ni(II) complexes. It was found that the trithiocyanuric dianion can act either as a bidentate ligand or be situated out of the coordination sphere of nickel. The crystal and molecular structure of [Ni(dpta)(ttcH)(H₂O)] H₂O was determined. Crystals are monoclinic, space group P2₁/n, with a = 20.316(4), b = 7.967(2), c = 21.401(4) Å, β = 99.23(3)°, K=3419.1(13)ų, Z = 4, T = 293 K. The nickel(II) atom is six-coordinated by three nitrogen atoms from dipropylene-triamine, nitrogen and sulphur from trithiocyanuric acid, and an oxygen atom from a water molecule in a distorted octahedral geometry.     

Structural and Spectroscopic Characterization of Two New Thallium(I)/Thiosaccharinate Complexes

The crystal structures of [Tl(tsac)] ( 1 ) and [Tl(tsac)(ophen)] ( 2 ) (tsac = anion of thiosaccharin; ophen = 1, 10 phenanthroline) have been determined at 116 K by single crystal X‐ray diffractometry. Complex 1 crystallizes in the monoclinic space group P2₁/a with Z = 4 and complex 2 in the monoclinic space group C2/c with Z = 8.In both complexes T^I is coordinated to a thiosaccharinate anion through its sulphur and nitrogen atoms. A distorted eight fold coordination sphere around the cation in complex 1 is completed with two other longer Tl‐S bonds and four Tl···O contacts with five symmetry related neighbouring thiosaccharinate anions. A phenanthroline molecule acting as a bidentate ligand through its nitrogen atoms completes a four‐fold coordination around the metal atom in complex 2 . The infrared spectra of both complexes were also recorded and their most important features discussed on the basis of its structural peculiarities.     

Funktionalisierte Alkinkomplexe von Wolfram(VI). Synthese und Kristallstrukturen von [WCl4(Et?Se?CC?Se?Et)(THF)] und [WCl4(Et?Te?CC?Te?Et)(THF)]

Functionalized Alkyne Complexes of Tungsten(VI). Syntheses and Crystal Structures of [WCl₄(Et? Se? C?C? Se? Et)(THF)] and [WCl₄(Et? Te? C?C? Te? Et)(THF)] The title compounds have been prepared by reactions of [WCl₄(SEt₂)₂] with the alkynes Et? X? C?C? X? Et (X = Se, Te) in CCl₄ solution and subsequent addition of tetrahydrofurane. Both complexes were characterized by crystal structure determinations. [WCl₄(Et? Se? C?C? Se? Et)(THF)]: Space group P2₁/n, Z = 4, structure determination with 2942 unique reflections, R = 0.038. Lattice dimensions at 20°C: a = 934.2, b = 1639.5, c = 1189.5 pm, β = 96.497°. [WCl₄(Et? Te? C?C? Te? Et)(THF)]: Space group P2₁/n, Z = 4, structure determination with 4097 unique reflections, R = 0.067, Lattice dimensions at ?70°C: a = 899.2, b = 1691.9, c = 1213.3 pm, β = 96.82°. The complexes have monomeric molecular structures with the oxygen atom of the THF molecules in trans-position to the side-on bound alkyne ligands.     

Coordination compounds of nickel with trithiocyanuric acid. Part IV. Structure of [Ni(pmdien)(ttcH)] (pmdien = N,N,N′,N′,N′′-pentamethyldiethylenetriamine,ttcH3 = trithiocyanuric acid)

Ni^II mixed-ligand complexes of compositions [Ni(pmdien)(ttcH)] (1), [Ni(baphen)₂(ttcH)] · 4H₂O (2), [Ni-(dpa)(ttcH)(H₂O)] (3), [Ni(cyclam)(ttcH)] · 2H₂O (4), [Ni(hexaa)](ttcH) (5) and [Ni(hexab)(ttcH)] · 2H₂O (6), (baphen = 4,7-diphenyl-1,10-phenanthroline, dpa = 2,2-dipyridylamine, cyclam = 1,4,8,11-tetraazacyclotetradecane, hexaa = 1,3,6,9,11,14-hexaazatricyclo[12.2.1.1^6,9]-octadecane, hexab = 1,8-dimethyl-1,3,6,8,10,13-hexaazacyclotetradecane) have been prepared and characterized by means of i.r., u.v.–vis. spectroscopies and magnetochemical measurements. The redox properties of the complexes were studied by cyclic voltammetry. The crystal and molecular structure of [Ni(pmdien)(ttcH)] was determined. The nickel atom is penta-coordinated by three N atoms of pmdien, and by S and N atoms of trithiocyanurate(2–) anion.     

Characterization of Thallium(I) Saccharinate: an unprecedented Coordination of the Saccharinate Ligand

The crystal structure of [Tl₂(sac)₂(H₂O)]_n (sac = saccharinate anion) has been solved using single crystal X‐ray diffraction. It crystallizes in the triclinic space group P 1 with Z = 2 and presents a polymeric structure formed by two saccharinate anions, one water molecule and two chemically different Tl^I cations, one 8‐coordinate and the other 5‐coordinate. Saccharinate shows an unprecedented coordination behavior as it acts as chelating ligand through its N and carbonyl O atoms with the N atom interacting simultaneously with both metal centers, and participation of sulphonyl oxygen atoms in bonding. The most important features of the IR spectrum of the complex are discussed on the basis of the structural peculiarities.     

Trans‐bis(saccharinato)cadmium(II) Complexes with 2‐Pyridylethanol: Synthesis,Crystal Structures,Spectral and Thermal Characterization of [Cd(sac)2(pyet)2] and [Cd(sac)2(H2O)(dmso)(pyet)]

Two trans saccharinate (sac) complexes of cadmium(II) with 2‐pyridylethanol (pyet) were synthesized and characterized by elemental analyses, FT—IR spectroscopy, thermal analysis and single crystal X‐ray diffractometry. The [Cd(sac)₂(pyet)₂] ( 1 ) and [Cd(sac)₂(H₂O)(dmso)(pyet)] ( 2 ) complexes crystallize in the monoclinic (P2₁/c) and orthorhombic [P2₁2₁2₁] crystal systems, respectively. The sac ligands in both complexes are N‐coordinated and located in trans positions, while the pyet molecules act as a bidentate N‐ and O‐donor ligand forming two six‐membered chelate rings. Thermal decomposition of the complexes in air results in elimination of aqua, dmso and pyet ligands, respectively, forming cadmium saccharinate as a stable intermediate, which also decomposes at higher temperatures to give cadmium oxide.