Published by De Gruyter

Volume 60 Issue 9

Issue of Zeitschrift für Naturforschung B

Contents
Journal Overview

Open Access June 2, 2014

Münzmetall-Lanthanid-Chalkogenide: I. Kupfer(I)-Lanthanid(III)-Sulfide der Zusammensetzung CuMS₂ (M = La – Nd, Sm, Gd, Tb) im monoklinen A-Typ / Coinage Metal Lanthanide Chalcogenides: I. Copper(I) Lanthanide(III) Sulfides of the Composition CuMS₂ (M = La – Nd, Sm, Gd, Tb) with the Monoclinic A-Type Structure

Sabine Strobel, Petra Lauxmann, Thomas Schleid

Page range: 917-923

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Abstract

Single crystals of the ternary copper(I) lanthanide(III) sulfides with the composition CuMS 2 (M = La - Nd, Sm, Gd, Tb) form within seven days at 800 °C by oxidation of elemental copper and lanthanide metal with sulfur (molar ratio: 1 : 1 : 2) in evacuated silica tubes when equimolar quantitites of CsCl are present as flux. The crystal structures (monoclinic, P2 1 /c, Z = 4; e. g. CuLaS 2 : a = 662.04(6), b = 730.89(6), c = 692.73(6) pm, β = 98.741(7)° and CuTbS 2 : a = 639.13(6), b = 700.02(6), c = 670.46(6) pm, β = 98.214(7)°) exhibit corrugated layers 2 ∞ {[Cu(S1) 3/3 (S2) 1/1 ] 3− } parallel to (100) which consist of vertex-linked pairs of [CuS 4 ] 7− tetrahedra sharing a common edge ([Cu 2 S 6 ] 10− ). Their three-dimensional cross-linkage is achieved by M 3+ cations in monocapped trigonal prismatic coordination of seven S 2− anions. The metal sulfur distances in the [CuS 4 ] 7− units cover with 230 - 233 (Cu-S2) and 231 - 238 (Cu-S1) as well as 241 - 248 (Cu-S1’) and 245 - 251 pm (Cu-S1”) a rather broad range, whereas those within the [MS 7 ] 11− polyhedra lie relatively closer together (M-S: 276 - 307 pm). The present work is the first comprehensive account of the knowledge acquired from X-ray single-crystal diffraction data for the whole isotypic series CuMS 2 (M = La - Nd, Sm, Gd, Tb).

Open Access June 2, 2014

Derivate der 1,3-Dimethyl-5-methylen-barbitursüure / Derivatives of 1,3-Dimethyl-5-methylenebarbituric Acid

Norbert Kuhn, Alois Kuhn, Elke Niquet, Manfred Steimann, Kamal Sweidan

Page range: 924-928

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Abstract

1,3-Dimethylbarbituric acid (1, R = Me) reacts with aqueous formaldehyde in the presence of pyridine to give 1,3-dimethyl-2,4,6-trioxo-5-pyridinomethyl-1,3-perhydrodiazin-5-ylpyridinium ylide (6) in good yield. From 6 and 2,3-dihydro-1,3-diisopropyl-4,5-dimethylimidazol- 2-ylidene (7), the zwitterionic imidazolium derivative 1,3-dimethyl-2,4,6-trioxo-5-(1,3-diisopropyl- 4,5-dimethylimidazoliomethyl)-1,3-perhydrodiazin-5-yl-imidazolium ylide (8) is obtained. Similarly, the phosphonium compound 1,3-dimethyl-2,4,6-trioxo-5-triphenylphosphoniomethyl-1,3- perhydrodiazin-5-y l-phosphonium ylide (9) is obtained from 6 and PPh 3 . The crystal structures of 8 and 9 are reported.

Open Access June 2, 2014

Compounds Ln₅(Ag, Ga)_{19 – x} (Ln = Gd, Tb) – Defective Partially Ordered Representatives of the Rb₅Hg₁₉ Structure Type

Roman V. Gumeniuk, Lev G. Akselrud, Yurij B. Kuz’ma

Page range: 929-932

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Abstract

New compounds Ln 5 (Ag, Ga) 19−x (Ln = Gd, Tb) have been found to crystallise with the Rb 5 Hg 19 structure type (space group I4/m). The crystal structures were refined for Gd 5 Ag 1.8 Ga 15 and Tb 5 Ag 2 Ga 15.6 from X-ray powder data: a = 9.4635(1), c = 9.8638(2) Å , R I = 0.093 and a = 9.4313(1), c = 9.8491(2) Å , R I = 0.085, respectively. Some positions in the crystal structures of new the compounds are occupied partially.

Open Access June 2, 2014

The Stannide LiRh₃Sn₅ – Synthesis, Structure, and Chemical Bonding

Puravankara Sreeraj, Dirk Johrendt, Helen Müller, Rolf-Dieter Hoffmann, Zhiyun Wu, Rainer Pöttgen

Page range: 933-939

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Abstract

The lithium rhodium stannide LiRh 3 Sn 5 was synthesized from the elements in a sealed tantalum tube and investigated via X-ray powder and single crystal diffraction: Pbcm, a = 538.9(1), b = 976.6(3), c = 1278.5(3) pm, wR2 = 0.0383, 1454 F 2 values, and 44 variables. Refinement of the occupancy parameters revealed a lithium content of 92(6)%. LiRh 3 Sn 5 crystallizes with a new structure type. The structure is built up from a complex three-dimensional [Rh 3 Sn 5 ] network, in which the lithium atoms fill channels in the b direction. The [Rh 3 Sn 5 ] network is governed by Rh-Rh (274 - 295 pm), Rh-Sn (262 - 287 pm), and Sn-Sn (289 - 376 pm) interactions. The lithium atoms have CN 13 (4 Rh+9 Sn). Electronic band structure calculations and the COHP bond analysis reveal strong Rh−Sn bonds and also significant Rh−Rh bonding within the Rh 3 Sn 5 network, which is additionally stabilized by weak but frequent Sn−Sn interactions.

Open Access June 2, 2014

Synthesis, Crystal Structure, and Spectroscopic and Magnetic Properties of a Dinuclear Iron(III) Complex Asymmetrically Bridged by a Phenoxo and a Methoxo Group

C. T. Zeyrek, A. Elmali, Y. Elerman

Page range: 940-944

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Abstract

A new dinuclear iron(III) derivative Fe 2 L(OCH 3 )Cl 2 (L = 1,3-bis[N-(5-chloro-2-hydroxybenzylidene)- 2-aminoethyl]-2-(5-chloro-2-hydroxyphenyl)imidazolidine) has been synthesized, it crystal structure determined and magnetically characterized. The two iron(III) ions are asymmetrically bridged by a phenoxo and a methoxo group and separated by 3.150(2)Å . The magnetic susceptibility of the complex was measured over the range 5 - 349.3 K and the observed data were successfully simulated by the equation based on the spin-Hamiltonian operator , indicating very weak antiferromagnetic coupling between the iron ions with J = −11.3 cm −1 . The magnetic and structural parameters of the compound and the nature of the magnetic super-exchange interaction are discussed and compared with data of similar dinuclear iron(III) complexes.

Open Access June 2, 2014

Synthesis and Structural Characterization of N-[4-(2-Hydroxyethyl)-1,2,4-oxathiazinan-3-ylidene]-benzamide and its Mercury(II) Chloride Adduct

Jorge R. Angulo-Cornejo, Ketty Ayala-León, Gabriel García Herbosa, José V. Cuevas, Virginia Diez, Rainer Richter, Lothar Hennig, Lothar Beyer

Page range: 945-950

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Abstract

The synthesis of N-[4-(2-hydroxyethyl)-1,2,4-oxathiazinan-3-ylidene]-benzamide (2a) and N-[4- (2-hydroxyethyl)-1,2,4-oxathiazinan-3-ylidene]-2-fluorobenzamide (2b) by oxidation of the corresponding 1,1-bis(2-hydroxyethyl)-3-aroylthioureas with potassium iodate in aqueous solution is reported. Variable temperature 1 H NMR spectra of 2a prove that the heterocyclic 1,2,4-(O, S,N) sixmembered ring is involved in a dynamic chair-boat conformational interconversion. Molecular mechanic calculations show that the chair conformation is more stable than the boat conformation by 3.0 kcal/mol. The synthesis of the adduct [(2a)·0.5 HgCl 2 ] 3 as well as the X-ray structural characterization of 2a and 3 are also reported.

Open Access June 2, 2014

Syntheses and Characterization of Two New 4,4’-Bithiazole d¹⁰ Complexes, Structural Characterization of M(DABTZ)₂(CH₃COO)](ClO₄) · 2H₂O (M = Zn, Cd)

Jafar Abedini, Ali Morsali

Page range: 951-954

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Abstract

New zinc(II) and cadmium(II) complexes of the 2,2’-diamino-4,4’-bithiazole (DABTZ) ligand, [M(DABTZ) 2 (CH 3 COO)](ClO 4 ), have been synthesized and characterized by elemental analysis, IR, 1H NMR and 13C NMR spectroscopy. The structural characterization of the Cd(DABTZ) 2 (CH 3 COO)](ClO 4 ) · 2H 2 O complex shows the complex to be a monomer and the Cd atom to be coordinated by four nitrogen atoms of the “DABTZ” ligands and two oxygen atoms of the acetate anion. There is an edge-to-edge π-π stacking interaction between the parallel aromatic rings.

Open Access June 2, 2014

The Five-, Six- and Seven-Vertex Dicarbaboranes, Monocarbaborane Anions and Borane Dianions with closo Structures. Nuclear Spin-Spin Coupling Constants Calculated by DFT Methods

Bernd Wrackmeyer

Page range: 955-961

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Abstract

Five-, six- and seven-vertex dicarbaboranes, carborane anions and borane dianions have been studied by DFT calculations at the B3LYP/6-311+G(d,p) level of theory, aiming at determining the indirect nuclear spin-spin coupling constants with an emphasis on J( 11 B, 11 B), J( 13 C, 11 B) and J( 13 C, 13 C). The reasonable agreement with all experimental data suggests that the calculated data can be used in the discussion of the bonding situation in these cluster compounds, for which many coupling constants cannot be determined experimentally. The delocalisation of electron density is reflected by changes in both magnitude and sign of the coupling constants. The trend in the coupling constants between nuclei in antipodal positions points towards direct bonding interactions.

Open Access June 2, 2014

Efficient and Rapid Regioselective Deprotection of Isopropylidene Ketals

Sakkarapalayam M. Mahalingam, Indrapal Singh Aidhen

Page range: 962-966

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Abstract

A simple and efficient protocol is described for the regioselective hydrolysis of terminal isopropylidene ketal protection in carbohydrate derivatives 1a - 11a. It uses either CoCl 2 · 2H 2 O in acetonitrile or InCl 3 in methanol at temperatures ranging from 50 to 60 °C. The low cost of CoCl 2 ·2H 2 O along with its requirement in catalytic quantities offers a great advantage for the multi-gram scale reaction.

Open Access June 2, 2014

Synthese und Ringumwandlungen von 1,2,5-Oxadiazinan-3,6-dionen / Synthesis and Ring Transformations of 1,2,5-Oxadiazinan-3,6-diones

Detlef Geffken, Hans von Zydowitz, Alf Ploetz

Page range: 967-972

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Abstract

1,2,5-Oxadiazinan-3,6-diones (8), easily available by cyclic carbonylation of α-amino-carbohydroxamic acids 7 with 1,1’-carbonyldiimidazole, are reacted with hydrazine to give 3- aminohydantoins (10). Depending on the substituents R 1 /R’ 8 was found to undergo an imidazole catalyzed oxidoreduction to 4-imidazolidinones (11) or α-iminophenylacetamides (12).

Open Access June 2, 2014

Isoflavonoids from Seeds of Millettia griffoniana (Bail), 15

Dieudonne Ngamga, Emanuel Yankep, Pierre Tane, Merhatibeb Bezabih, Bonaventure T. Ngadjui, Zacharia T. Fomum, Berhanu M. Abegaz

Page range: 973-977

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Abstract

Three new isoflavonoids, griffonianone F, G and H were isolated from the seeds of Millettia griffoniana, along with the known prebarbigerone, pseudobaptigenin, pseudobaptigenin methyl ether, tephrosin, dipterixine, odorantine, 7,4’,5’-tetramethoxyisoflavone and isojamaicin. Their structures were assigned on the basis of spectroscopic data and chemical transformations.

Open Access June 2, 2014

Silver(I)-Saccharinato Complexes with 2-(Aminomethyl)pyridine and 2-(2-Aminoethyl)pyridine Ligands: [Ag(sac)(ampy)] and [Ag₂(sac)₂(μ-aepy)₂]

Sevim Hamamci, Veysel T. Yilmaz, William T. A. Harrison

Page range: 978-983

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Abstract

Two new saccharinato-silver(I) (sac) complexes, [Ag(sac)(ampy)] (1), and [Ag 2 (sac) 2 (μ-aepy) 2 ] (2), [ampy = 2-(aminomethyl)pyridine, aepy = 2-(2-aminoethyl)pyridine], have been prepared and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the monoclinic space group P 2 1/c and triclinic space group P1̄, respectively. The silver(I) ions in both complexes 1 and 2 exhibit a distorted T-shaped AgN 3 coordination geometry. 1 consists of individual molecules connected into chains by N-H···O hydrogen bonds. There are two crystallographically distinct dimers in the unit cell of 2 and in each dimer, the aepy ligands act as a bridge between two silver(I) centers, resulting in short argentophilic contacts [Ag1···Ag1 = 3.0199(4) Å and Ag2···Ag2 = 2.9894(4) Å ]. Symmetry equivalent dimers of 2 are connected by N-H···O hydrogen bonds into chains, which are further linked by aromatic π(py)···π(py) stacking interactions into sheets.

Open Access June 2, 2014

Synthesis of Decaline Analogues of Isovelleral

M. Johansson, I. Aujard, D. Röme, H. Anke, O. Sterner

Page range: 984-989

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Abstract

Decaline analogues of the bioactive fungal sesquiterpene (+)-isovelleral (1a), retaining the bicyclo[4,1,0]hept-2-en-1,2-dicarbaldehyde system, were prepared, and their cytotoxic and antimicrobial activities were compared with those of the natural product. While the two isomers (±)-2 and (±)-3 were as active as isovelleral (1a), the isomer (±)-4 was approximately 10 times less potent.

Open Access June 2, 2014

Synthesis of Some New Linear and Chiral Macrocyclic Pyridine Carbazides as Analgesic and Anticonvulsant Agents

Abdel-Galil E. Amr

Page range: 990-998

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Abstract

A series of 2,6-disubstituted pyridine derivatives were prepared from 2,6-diacetylpyridine or 2,6- dicarbonyl pyridine dichloride as starting materials. Reaction of 2,6-diacetylpyridine 1 with hydroxylamine hydrochloride or different aromatic aldehydes afforded the corresponding 2,6-diacetylpyridine dioxime and 2,6-bis-[β -(2-thienyl)acryloyl]pyridine derivatives 2 and 3, respectively. Additionally, N 2 ,N 2‘ -(pyridine-2,6-dicarbonyl)-L-amino acid hydrazides 5 were prepared starting from 2,6- dicarbonyl pyridine dichloride via the corresponding esters 4. Compound 3 was reacted with hydroxylamine hydrochloride to afford the 2,6-bis-[β -(2-thienyl)acryloyl-oxime]-pyridine derivative 6. Treatment of compounds 2 or 6 with phenyl isocyanate or phenyl isothiocyanate in refluxing dioxane gave the corresponding semicarbazide or thiosemicarbazide derivatives 7 and 8, respectively. Their treatment with toluene-3,5-diisocyanate afforded the macrocyclic semicarbzides 9 and 10, respectively. The chiral thiosemicarbazides 11a,b were however, prepared by treating compounds 5a,b with phenyl isothiocyanate followed by cyclization with sodium hydroxide (2N) yielding the triazoles 12a,b. Finally, the hydrazides 5a,b were treated with toluene-3,5-diisocyanate to afford the chiral macrocyclic tetrapeptide semicarbazides 13a,b in reasonable yields, while the expected cyclic dipeptide 14 was not formed. The structure assignments of the new compounds were based on chemical and spectroscopic evidence. The pharmacological screening showed that many of these compounds have good analgesic and anticonvulsant activities comparable to Voltarine ® and Carbamazapine ® used as reference drugs.

Open Access June 2, 2014

Syntheses of New Pyridoxazines, Benzoxa(thia)azines, and Benzoxa(thia)azepines via Cyclocondensation and Elimination Reactions between Donors and Acceptors

Ashraf A. Aly, Alaa A. Hassan, Kamal M. El-Shaieb, Rafaat M. Shaker

Page range: 999-1005

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Abstract

Reaction of 3-amino-2-hydroxypyridine and 2-amino(thio)phenols with various selected π-acceptors are herein reported. Different modes of cyclization via elimination and/or condensation reactions were observed during the reaction of the donors with 3,4,5,6-tetrachloro-1,2-benzoquinone (CHLo), 2,3,5,6-tetrachloro-1,4-benzoquinone (CHL-p), 2,3-dicyano-1,4-naphthoquinone (DCNQ) and 2- dicyanomethyleneindane-1,3-dione (CNIND). A series of pyridoxazines, benzoxa(thia)azines, benzoxa( thia)azepines has been synthesized in good yields.

Open Access June 2, 2014

Eupatoric Acid: A Novel Triterpene from Eupatorium odoratum L. (Asteraceae)

Sajan Amatya, Sarbajna M. Tuladhar

Page range: 1006-1011

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Abstract

Phytochemical studies on the petroleum ether extract of the roots of Eupatorium odoratum have resulted in the isolation of a novel triterpene, 3β -hydroxy-28-carboxyolean-12-ene (1) along with seven known compounds - poriferasterol (2), octadecane (3), butyrospermol acetate (4), bis(2- ethylhexyl)phthalate (5), chrysophanol (6), physcion (7) and palmitic acid (8). Novel compound 1 is designated as eupatoric acid. Compounds 2 - 7 were reported here for the first time from this plant. Palmitic acid (8) was also isolated for the first time from this root. The structure of the novel compound was established on the basis of spectroscopic studies. The cytotoxicity of the compounds 1 - 7 was studied using a lethality test against Artemia salina (brine shrimp).

Open Access June 2, 2014

Guaianolide and seco-Guaianolide from Salvia nubicola (Lamiaceae)

Muhammad Shaiq Ali, Waqar Ahmed, Syed Amir Ibrahim

Page range: 1012-1015

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Abstract

A sesquiterpene-lactone of the guaianolide class (nubenone) and a seco-guaianolide (nubenoic acid) have been isolated from Salvia nubicola collected in Quetta, Pakistan. Structures of both sesquiterpenes were elucidated with the aid of spectroscopic techniques including two dimensional NMR spectroscopy.

Open Access June 2, 2014

Synthesis and Structure of Pyrrolidinobromodiboranes(4)

Yong Nie, Hans Pritzkow, Walter Siebert

Page range: 1016-1019

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Abstract

The reaction of tetrapyrrolidinodiborane(4) (1) with BBr 3 in a 1:1 molar ratio yields a mixture of 1,2-dibromo-1,2- dipyrrolidinodiborane(4) (2) and bromotripyrrolidino- diborane( 4) (3), while a 1:2 molar ratio leads in Et 2 O to compound 2 as the main product along with a small amount of [(C 4 H 8 N) 2 B 2 Br 3 (OEt)] (4). The new compounds have been characterized by NMR and MS data, as well as by X-ray structure analyses of 2 and 4, of which the former exhibits an interesting polymorphism phenomenon.

About this journal

Objective
Zeitschrift fuer Naturforschung B (ZNB) publishes novel research in all areas of inorganic chemistry, organic chemistry, and analytical chemistry. In particular, the journal focuses on solid state chemistry, coordination chemistry, main group element chemistry, synthetic organic chemistry, natural product chemistry and, to a lesser extent, on analytical chemistry. For more than 65 years Zeitschrift fuer Naturforschung B has been open to contributions from all fields of experimental and theoretical chemistry. Zeitschrift fuer Naturforschung B publishes 12 issues per volume/year. Sometimes double issues occur.

Topics

Solid state chemistry
Coordination chemistry
Main group element chemistry
Organic chemistry
Natural product chemistry

Article formats
Original (full) papers, research notes and preliminary communications, reports on specific research topics of current interest (reviews)

> Information on submission process

Volume 60 Issue 9

Issue of Zeitschrift für Naturforschung B

Abstract

Derivate der 1,3-Dimethyl-5-methylen-barbitursüure / Derivatives of 1,3-Dimethyl-5-methylenebarbituric Acid

Abstract

Compounds Ln5(Ag, Ga)19 – x (Ln = Gd, Tb) – Defective Partially Ordered Representatives of the Rb5Hg19 Structure Type

Abstract

The Stannide LiRh3Sn5 – Synthesis, Structure, and Chemical Bonding

Abstract

Synthesis, Crystal Structure, and Spectroscopic and Magnetic Properties of a Dinuclear Iron(III) Complex Asymmetrically Bridged by a Phenoxo and a Methoxo Group

Abstract

Synthesis and Structural Characterization of N-[4-(2-Hydroxyethyl)-1,2,4-oxathiazinan-3-ylidene]-benzamide and its Mercury(II) Chloride Adduct

Abstract

Syntheses and Characterization of Two New 4,4’-Bithiazole d10 Complexes, Structural Characterization of M(DABTZ)2(CH3COO)](ClO4) · 2H2O (M = Zn, Cd)

Abstract

The Five-, Six- and Seven-Vertex Dicarbaboranes, Monocarbaborane Anions and Borane Dianions with closo Structures. Nuclear Spin-Spin Coupling Constants Calculated by DFT Methods

Abstract

Efficient and Rapid Regioselective Deprotection of Isopropylidene Ketals

Abstract

Synthese und Ringumwandlungen von 1,2,5-Oxadiazinan-3,6-dionen / Synthesis and Ring Transformations of 1,2,5-Oxadiazinan-3,6-diones

Abstract

Isoflavonoids from Seeds of Millettia griffoniana (Bail), 15

Abstract

Silver(I)-Saccharinato Complexes with 2-(Aminomethyl)pyridine and 2-(2-Aminoethyl)pyridine Ligands: [Ag(sac)(ampy)] and [Ag2(sac)2(μ-aepy)2]

Abstract

Synthesis of Decaline Analogues of Isovelleral

Abstract

Synthesis of Some New Linear and Chiral Macrocyclic Pyridine Carbazides as Analgesic and Anticonvulsant Agents

Abstract

Syntheses of New Pyridoxazines, Benzoxa(thia)azines, and Benzoxa(thia)azepines via Cyclocondensation and Elimination Reactions between Donors and Acceptors

Abstract

Eupatoric Acid: A Novel Triterpene from Eupatorium odoratum L. (Asteraceae)

Abstract

Guaianolide and seco-Guaianolide from Salvia nubicola (Lamiaceae)

Abstract

Synthesis and Structure of Pyrrolidinobromodiboranes(4)

Abstract

Compounds Ln₅(Ag, Ga)_{19 – x} (Ln = Gd, Tb) – Defective Partially Ordered Representatives of the Rb₅Hg₁₉ Structure Type

The Stannide LiRh₃Sn₅ – Synthesis, Structure, and Chemical Bonding

Syntheses and Characterization of Two New 4,4’-Bithiazole d¹⁰ Complexes, Structural Characterization of M(DABTZ)₂(CH₃COO)](ClO₄) · 2H₂O (M = Zn, Cd)

Silver(I)-Saccharinato Complexes with 2-(Aminomethyl)pyridine and 2-(2-Aminoethyl)pyridine Ligands: [Ag(sac)(ampy)] and [Ag₂(sac)₂(μ-aepy)₂]