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A three-part experiment that leads to the synthesis of palladium(II) complex starting from a C[subscript 3]-symmetric triaminoguanidinium-based ligand is presented. In the first part, the preparation of tris-benzylidenetriaminoguanidinium chloride ([H[subscript 6]Br[subscript 3]L]Cl) by an acidic catalyzed 3-fold imine formation reaction of 5-bromo-2-hydroxybenzaldehyde and triaminoguanidinium chloride is described. Starting from the second part, the reaction procedures are performed under inert gas atmosphere. The conversion of PdCl[subscript 2] with acetonitrile to give [Pd(MeCN)[subscript 4]]Cl[subscript 2] as a precursor is performed at 80 °C. The third part of the experiment is a three-step procedure that begins with deprotonation of [H[subscript 6]Br[subscript 3]L]Cl, followed by transfer of [Pd(MeCN)[subscript 4]]Cl[subscript 2] to the reaction flask, where the chelation of Pd(II)-precursor leads to the in situ species [Pd(MeCN)H[subscript 3]Br[subscript 3]L]. Addition of PPh[subscript 3] as the final reaction step yields [Pd(PPh[subscript 3])H[subscript 3]Br[subscript 3]L]. This sequence of experiments provides an excellent example of ligand and transition metal preparation and its subsequent complexation to form an oxidant-sensitive organometallic species. Undergraduate students get the opportunity to learn Schlenk techniques and to investigate [superscript 1]H NMR spectra of organic and organometallic compounds starting from relatively simple to more advanced spectra. The distinct result of the chemical shift of the [superscript 4]J[subscript P-H]-affected doublet mirrors the preparative success of the student and demonstrates the utility of [superscript 1]H NMR experiments.

Novel cobalt(II) containing compounds of tris‐(2‐pyridinylene‐N‐oxide)triaminoguanidine ligands L2− are presented: the supramolecular metallocycle [Co6(OOCMe)3(NCS)3L3]4 and the one‐dimensional coordination polymer {[Co3(μ‐OOCMe)3L]NO3}n. Analog zinc(II) complexes show similar to identical structures that are slightly influenced by different preferences regarding the coordination number. In the polymers, the coordination number is five, which is less common for zinc(II) and rare for cobalt(II). The compounds are characterized by single‐crystal as well as powder X‐ray diffraction, IR spectroscopy, and ESI mass spectrometry. Magnetic measurements revealed predominantly antiferromagnetic exchange interaction between the cobalt(II) centers linked by the triaminoguanidine backbone. [ABSTRACT FROM AUTHOR]

Reactions of 2,2'-dithiobis(pyridine N-oxide) with various ZnII metal precursors and HgII halides are investigated and the products structurally characterized by X-ray crystallography. The crystal structures of the heteroleptic dinuclear complexes [HgX2(pyrithionate)2] (X = Br, I) are reported for the first time and that of the widely used antifungal and antifouling agent, the homoleptic dinuclear complex [Zn2(pyrithionate)4] (zinc pyrithione), is redetermined at low temperature, thereby improving the previous room temperature study in terms of precision. The encountered anionic chelate ligand pyrithionate results from reductive cleavage of the disulfide bond of 2,2'-dithiobis(pyridine N-oxide). [ABSTRACT FROM AUTHOR]

Reactions of 2,2'-dithiobis(pyridine N-oxide) with various ZnII metal precursors and HgII halides are investigated and the products structurally characterized by X-ray crystallography. The crystal structures of the heteroleptic dinuclear complexes [HgX2(pyrithionate)2] (X = Br, I) are reported for the first time and that of the widely used antifungal and antifouling agent, the homoleptic dinuclear complex [Zn2(pyrithionate)4] (zinc pyrithione), is redetermined at low temperature, thereby improving the previous room temperature study in terms of precision. The encountered anionic chelate ligand pyrithionate results from reductive cleavage of the disulfide bond of 2,2'-dithiobis(pyridine N-oxide). [ABSTRACT FROM AUTHOR]

C10H8Cl2N2S2Zn, monoclinic, C2/c (no. 15), a = 12.317(2) Å, b = 9.868(2) Å, c = 10.947(2) Å, β = 92.37(2)°, V = 1329.3 Å3, Z = 4, Rgt(F) = 0.036, wRref(F2) = 0.132, T = 110 K.

The syntheses of the novel silicon‐bridged tris(tetraorganotin) compounds MeSi(CH2SnPh2R)3 (2, R=Ph; 5, R=Me3SiCH2) and their halogen‐substituted derivatives MeSi(CH2SnPh(3−n)In)3 (3, n=1; 4, n=2) and MeSi(CH2SnI2R)3 (6, R=Me3SiCH2) are reported. The reaction of compound 4 with di‐t‐butyltin oxide (t‐Bu2SnO)3 gives the oktokaideka‐nuclear (18‐nuclear) molecular diorganotin oxide [MeSi(CH2SnPhO)3]6 (7) while the reaction of 6 with sodium hydroxide, NaOH, provides the trikonta‐nuclear (30‐nuclear) molecular diorganotin oxide [MeSi(CH2SnRO)3]10 (8, R=Me3SiCH2). Both 7 and 8 show belt‐like ladder‐type macrocyclic structures and are by far the biggest molecular diorganotin oxides reported to date. The compounds have been characterized by elemental analyses, electrospray mass spectrometry (ESI‐MS), NMR spectroscopy, 1H DOSY NMR spectroscopy (7), IR spectroscopy (7, 8), and single‐crystal X‐ray diffraction analysis (2, 7, 8). [ABSTRACT FROM AUTHOR]

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The reexamination of the preparation of the cage compound has disclosed an incorrect structure of photodimer, as well as the putatively isolated intermediate. These products are reassigned as monomeric pyramidalized alkene and spirocyclic dichloride.

The development of a domino redox process under Willgerodt-Kindler conditions, which transforms a simple butanone side chain of suitable functionalized arenes and hetarenes into tricyclic annulated thieno[3,2-b]-thiophenes is reported. The key step in the synthesis included a nucleophilic aromatic substitution with an intermediary thioenolate.

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)