Jakob Hey

Assembly and Stepwise Oxidation of Interpenetrated Coordination Cages Based on Phenothiazine

A breath of fresh air is sufficient for the eightfold S-monooxygenation of an interpenetrated double cage based on eight phenothiazine ligands and four square-planar-coordinated Pd(II) cations. Besides these two cages, which were both characterized by X-ray crystallography, an eightfold S-dioxygenated double-cage was obtained under harsher oxidation conditions.

Syntheses of group 7 metal carbonyl complexes with a stable N-heterocyclic chlorosilylene.

Two structurally characterized manganese [L(2)Mn(CO)(4)](+)[Mn(CO)(5)](-) (1) and rhenium [L(3)Re(CO)(3)](+)[ReCO)(5)](-) (2) silylene complexes were prepared in one pot syntheses by reacting 1 equivalent of Mn(2)(CO)(10) with 2 equivalents of stable N-heterocyclic chlorosilylene L {L = PhC(NtBu)(2)SiCl} and 1 equivalent of Re(2)(CO)(10) with 3 equivalents of L in toluene at room temperature. Both complexes 1 and 2 were characterized by single-crystal X-ray structural analysis, NMR and IR spectroscopy, EI-MS spectrometry, and elemental analysis.

Striking Stability of a Substituted Silicon(II) Bis(trimethylsilyl)amide and the Facile Si–Me Bond Cleavage without a Transition Metal Catalyst

Silicon(II) bis(trimethylsilyl)amide (LSiN(SiMe(3))(2), L= PhC(NtBu)(2)) (2) has been synthesized by the reaction of LSiHCl(2) with KN(SiMe(3))(2) in 1:2 molar ratio in high yield where 1 equiv of the latter functions as a dehydrochlorinating agent. 2 exhibits a high stability up to 154 °C and can be handled in open air for a short period of time without any appreciable decomposition. An amazing five-membered cyclic silene (3) results from the cleavage of one Si-Me bond of 2 with an adamantyl phosphaalkyne. 3 is the first example of a heavy cyclopentene derivative which consists of four different elements, C, N, Si, and P. Both compounds are characterized by multinuclear NMR spectroscopy, EI-mass spectrometry, and single crystal X-ray diffraction studies.

Facile Access to Transition-Metal–Carbonyl Complexes with an Amidinate-Stabilized Chlorosilylene Ligand

Three transition-metal-carbonyl complexes [V(L)(CO)(3)(Cp)] (1), [Co(L)(CO)(Cp)] (2), and [Co(L(2))(CO)(3)](+)[CoCO)(4)](-) (3), each containing stable N-heterocyclic-chlorosilylene ligands (L; L=PhC(NtBu)(2)SiCl) were synthesized from [V(CO)(4)(Cp)], [Co(CO)(2)(Cp)], and Co(2)(CO)(8), respectively. Complexes 1-3 were characterized by NMR and IR spectroscopy, EI-MS spectrometry, and elemental analysis. The molecular structures of compounds 1-3 were determined by single-crystal X-ray diffraction.

An Inclusion Complex of Hexamolybdate inside a Supramolecular Cage and Its Structural Conversion

A self-assembled cage compound consisting of four concave ligands and two square-planar-coordinated Pd(II) ions was found to quantitatively encapsulate a hexamolybdate dianion [Mo(6)O(19)](2-) in solution. The addition of 1 equiv more of [Mo(6)O(19)](2-) to the inclusion complex resulted in the formation of a precipitate from which single crystals were grown. X-ray analysis showed that a structural conversion had taken place upon crystallization: one hexamolybdate anion was found to be wrapped in a chiral, cyclic arrangement of three ligands in the absence of any Pd(II) ions to give a compound of the formula {[Mo(6)O(19)](2-)@(ligand)(3)+2H(+)}. We postulate the stabilization of this arrangement by attractive C-H···O and CF(3)-pyridine interactions.

Formation of Silicon Centered Spirocyclic Compounds: Reaction of N-Heterocyclic Stable Silylene with Benzoylpyridine, Diisopropyl Azodicarboxylate, and 1,2-Diphenylhydrazine

Three silicon centered spirocyclic compounds 1-3, possessing silicon fused six- and five-membered rings have been prepared by the reaction of NHSi (L) [L = CH{(C=CH(2))(CMe)(2,6-iPr(2)C(6)H(3)N)(2)}Si] with benzoylpyridine, diisopropyl azodicarboxylate, and 1,2-diphenylhydrazine, respectively, in a 1:1 ratio. The three spirocyclic compounds (1- 3) were obtained by three different pathways. The reaction of L with benzoylpyridine leads to the activation of the pyridine ring, and dearomatization occurred. Treatment of diisopropyl azodicarboxylate with L favors a [1 + 4]- rather than a [1 + 2]-cycloaddition product, and the azo compound was converted to hydrazone derivative. Finally the reaction of 1,2-diphenylhydrazine and L results in the elimination of hydrogen by activating one of the C-H bonds present in the phenyl ring. All three complexes 1- 3 were characterized by single crystal X-ray structural analysis, NMR spectroscopy, EI-MS spectrometry, and elemental analysis. In addition the optimized structures of probable products and possible intermediates were investigated using density functional theory (DFT) calculations.