Synthesis and Structure of the [Co(NioxH)2(Thio)2]2[SiF6] Complex

Anhydrous compound [Co(NioxH)₂(Thio)₂]₂[SiF₆] (I) was synthesized. Its structure was determined by X-ray diffraction analysis. The structures and character of intramolecular and intermolecular hydrogen bonds of complex Iand the previously studied [Co(NioxH)₂(Thio)₂]₂[SiF₆] · 3H₂O complex were compared.     

The structure of polynuclear clusters based on zinc and copper compounds with thiosemicarbazidodiacetic acid

Polynuclear complexes were synthesized from Zn(II) and Cu(II) compounds and thiosemicarbazidodiacetic acid and their structures were studied. The formation of four-, five-, and nonanuclear clusters was shown to depend on the metal nature and the synthesis conditions.     

Transition metal complexes with thiosemicarbazide-based ligands,IV: Synthesis and molecular structure of 5-nitrosalicylaldehyde S-methylisothiosemicarbazonato-piperidine-copper(II)

Summary The reaction of warmDMF solutions of Cu(II) perchlorate, 5-nitrosalicylaldehyde S-methylisothiosemicarbazone (H₂ L) and piperidine (Pip) yielded the paramagnetic (_eff=2.19 B.M.) Cu(L)Pip complex, whereL is the dianionic form of H₂ L, formed as a result of deprotonation of the phenolic hydroxyl and NH₂ group. Crystal data of the complex are: monoclinic P2₁,a=11.902(4),b=6.765(3),c=11.343(4)Å; =112.92°,V=841.20(8)ų,M=400.9,Z=2,d ₀=1.60 gcm^–3,d _c =1.58 gcm^–3,F(000)=424. The structure was refined to a residualR=0.047. The copper(II) ion is coordinated in a square-planar arrangement by the piperidine nitrogen and the NNO set of donor atoms ofL.

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Komplexe der Übergangsmetalle mit Thiosemicarbazid-Liganden, IV. Synthese und molekulare Struktur von 5-Nitrosalicylaldehyd-S-methylisothiosemicarbazonato-piperidin-kupfer(II)

Zusammenfassung Durch die Reaktion in warmenDMF-Lösungen von Cu(II) Perchlorat, 5-Nitrosalicylaldehyd-S-methylisothiosemicarbazon (H₂ L) und Piperidin (Pip) wurde ein paramagnetischer Komplex (_eff=2.19 B.M.) Cu(L)Pip erhalten, wobeiL nach doppelter Deprotonierung (NH₂- und Phenolhydroxyl-Gruppe) als dianionische Form von H₂ L vorliegt. Die kristallographischen Daten des Komplexes sind: monokline Raumgruppe P2₁,a=11.902(4),b=6.765(3),c=11.343(4)Å, =112.92°;V=841.20ų,M=400.9,Z=2,d ₀=1.60 gcm^–3,d _c =1.58 gcm^–3,F(000)=424. Die struktur wurde bis zu einemR-Wert von 0.047 verfeinert. Die Koordination des Kupfers wird quadratisch-planar über den Piperidin-Stickstoff und die NNO-Donorhülle der Chelatliganden gebildet.

     

Cobalt(III) α-Dimethylglyoximates [Co(DH)2(Py)2]2SiF6 · 10H2O and [Co(DH)2(Thio)2]2SiF6 · 2H2O · C2H5OH: Synthesis and Structure

[Co(DH)₂(Py)₂]₂SiF₆ · 10H₂O and [Co(DH)₂(Thio)₂]₂SiF₆ · 2H₂O · C₂H₅OH complexes are synthesized and characterized by X-ray diffraction analysis. Two radicals of -glyoxime linked by hydrogen O–H···O bonds lie in the equatorial plane of the octahedral Co(III) complexes. Intramolecular (– and N–H···O) and intermolecular (O–H···F, O–H···O, N–H···F, N–H···O, N–H···S) interactions are discovered in the crystal. The influence of nonvalence interactions on the structures is discussed.     

Host-guest chemistry of the chromium-wheel complex [Cr8F8(tBuCO2)16]: prediction of inclusion capabilities by using an electrostatic potential distribution determined by modeling synchrotron X-ray structure factors at 16 K

The structure and detailed electron density distribution (EDD) of the large octanuclear chromium-wheel host complex [Cr8F8(tBuCO2)16] (1) has been determined from synchrotron X-ray structure factors collected at 16(5) K. The complex has a central cavity with a minimum entry distance between carbon atoms of the pivalate methyl groups (pivalic acid = tBuCO2H) of 4.027(4) A on one side of the molecule and 7.273(4) A on the other. The screened side of the molecule can be "opened" by rotation of methyl groups to create a strained host structure, which is compensated for by improved host-guest and host-solvent interaction. The EDD of the 272-atom complex (1144 e-) was determined by multipole modeling based on the experimental structure factors. 3d orbital populations on the Cr atoms and topological analysis of the EDD show that the covalent part of the metal-ligand interactions consists mainly of sigma donation from the ligands, but that overall the interactions are predominantly electrostatic. The electrostatic potential (EP) has been calculated from the experimental EDD. Knowledge of the geometry of the naked complex 1 as well as the EP in the central cavity of this molecule allows us to deduce which characteristic properties guest molecules must have to be accepted into the void. To probe these predictions, a series of complexes of 1 with different guest inclusions were synthesized (2 = 1 + N,N'-dimethylformamide (DMF), 3 = 1 + N,N'-dimethylacetamide (DMA), 4 = 1 + DMA + DMF, 5 = 1 + 2CH3CN), and their structures were examined by using X-ray diffraction data measured at 120(1) K. Results of these studies indicate that in the crystalline state, the optimal guest molecule should be linear and possess a permanent dipole. Attempts to crystallize the host complex with cations incorporated into the cavity were fruitless, although electrospray ionization mass spectrometry showed that a [1 + potassium]+ entity pre-exists in solution and can be transferred intact into the gas phase.     

The Use of Co(III) Dimethylglyoximates in the Biosynthesis of Rhizopus arrhizus Pectinases

Novel coordination compounds of Co(III) with dimethylglyoxime were synthesized, namely, [Co(DH)₂(Thio)₂]₃F[SiF₆] · 1.5H₂O (I) and [Co(DH)(Thio)₂]₂[SiF₆] · 3H₂O (II)], in which the central atom coordinates dimethylglyoxime moieties (DH), thiocarbamide (Thio), and hexafluorosilicate anions. These compounds were tested as stimulators in the biosynthesis of extracellular enzymes in the Rhizopus strain. It was established that the effect produced by complex compounds depends on the type of hydrolytic enzyme complex used, the composition of the complex, and its concentration in the cultivation medium.     

Crystal and molecular structure of chloro-bis(1,2-cyclohexanedione-dioxime)triphenylphosphinecobalt(III)

The structure of chloro-bis(1,2-cyclohexanedionediaxwte)triphenylphosphinecobalt(III) [Co(NioxH)₂PPh₃Cl] was determined by X-ray diffraction analysis. The crystal is monoclinic, a = 17.049(3), b = 15.223(3), c = 11.032(3) å, Β = 87.44(2)?, R(hkl) = 0.068 for 2739 reflections with I ≥2Σ(I). The structure is molecular. In the octahedral complex, the cobalt(III) atom is coordinated by two NioxH residues (av Co-N = 1.876 å), the phosphorus atom (Co-P = 2.307 å), and the Cl^- union (Co-Cl = 2.260 å). In the crystal, there are weak intermolecular interactions C-H…Cl and C-H…O.     

Crystal structure of benzoylformic acid thiosemicarbazone

Institute of Applied Physics, Academy of Sciences of the Moldavian SSR. Institute of Chemistry, Academy of Sciences of the Moldavian SSR. Burevestnik [Stormy Petrel] Scientific-Industrial Association, Leningrad. Translated from Zhurnal Strukturnoi Khimii, Vol. 29, No. 5, pp. 166–169, September–October, 1988.