In the square-planar cycloplatinated complex of R-phenylethylamine, both additional substituents, an anionic iodo and a neutral donor ligand, have been replaced by chelating ethylenediamine. A very ...pronounced trans influence is observed in the cationic product complex: Two significantly different bond distances to the chelating ligand are found, the longer in trans geometry to the coordinated carbon atom. The positive charge of the monocationic complex is balanced by an uncoordinated iodide. This target solid crystallizes with four independent cations and anions in the unit cell; pairs of complex cations related by pseudo-inversion are stabilized by T stacking. Classical N-H I hydrogen bonds lead to a layer structure in the (0 1 0) plane.
The chain polymer {Cd(μ-X)2py2}1∞ (X = Cl, Br; py = pyridine) undergoes a fully reversible phase transition between a monoclinic low-temperature and an orthorhombic high-temperature phase. The ...transformation can be directly monitored in single crystals and can be confirmed for the bulk by powder diffraction. The transition temperature can be adjusted by tuning the composition of the mixed-halide phase: Transition temperatures between 175 K up to the decomposition of the material at ca. 350 K are accessible. Elemental analysis, ion chromatography and site occupancy refinements from single-crystal X-ray diffraction agree with respect to the stoichiometric composition of the samples.
The organoplatinum complex of a primary amine and AgClO4 aggregate in methanol to oligonuclear mixed‐metal species. A perchlorate salt 3 with the empirical formula C96H146Ag7Cl13N12O62Pt6 could be ...isolated and structurally characterized with the help of X‐ray diffraction at the DESY synchrotron. The product contains both a penta‐ and a tetra‐nuclear complex cation in which Ag(I) and Pt(II) alternate, held together without any conventional bridge. The cationic species feature short Ag⋅⋅⋅Pt distances between 2.7 and 2.9 Å and contacts longer than 2.4 Å between Ag and C atoms in aromatic rings. In addition to the interactions with Ag(I) cations, Pt(II) is in a square‐planar arrangement, coordinated by a chelating and a terminal amine and an aqua ligand. The central Ag(I) in the pentanuclear cation is located on a twofold crystallographic axis and not involved in any obvious coordinative bond; it exclusively shows short contacts to the neighboring Pt(II) ions and the Pt‐bonded, formally anionic carbon atoms of the cyclometallated organic ligand. Powder diffraction shows that 3 melts and re‐solidifies without decomposition.
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•Coordination of betaine to alkaline earth (new!) and rare earth cations.•Syntheses from solution and via grinding were investigated.•Neutral zwitterionic ligand allows for multiple ...coordination modes.•Hardly predictable stoichiometries were observed.•Structures range from mono- over oligonuclear to coordination polymers.
We report the synthesis and structure of coordination compounds in which betaine acts as a ligand towards Pearson-hard cations. The overall neutral zwitterion was reacted with the corresponding nitrate salts in polar protic solvents such as water or methanol or mechanochemically by grinding the reaction partners. Reaction of MgII, CaII, SrII and BaII resulted in the first alkaline earth derivatives of betaine. The products comprise mono- and oligonuclear cations for the light, and cationic chain polymers for the heavy group2 metals. In the case of CaII, the betaine stoichiometry was decisive for the outcome of the reaction; solids with 1:4 and the less intuitive 3:16 cation to ligand ratio have been structurally characterized. Coordination numbers increase from six for MgII and CaII over seven and eight for the two independent SrII to eight for BaII cations. Coordination of betaine to trivalent Y, La and Pr results in the formation of structurally related dinuclear cations, with coordination numbers eight for Y and nine for the larger lanthanides. Water and betaine compete for coordination; aqua ligands prevail for the smaller, betaine for the larger cations. Betaine coordination to all these hard cations occurs in various modes, similar to those of other carboxylates. Bridging betaine subtends cation⋯cation distances between 4.5 and 6.1 Å. Nitrate coordination was only observed in the BaII chain polymer.
Oxidative addition allows to synthesize the first cycloplatinated primary amines in which the platinum adopts oxidation state +IV: Square planar organoplatinum(II) complexes can be converted with ...elementary diiodine and dibromine to the corresponding pseudo-octahedral Pt(IV) derivatives. The reaction may be monitored with the help of NMR spectroscopy and five of the target products have been characterized by single crystal X-ray diffraction. Two of these Pt(IV) complexes provide structural evidence for cis addition of the halogen and for the pronounced trans effect of the Pt–C bond. The latter is also reflected in a substitution reaction promoted by AgBF4: The halide substituent trans to the C in the coordination sphere can be selectively replaced by the pseudohalide cyanate. In the absence of a suitable silver salt, the pseudo-octahedral Pt(IV) complexes are inert in substitution reactions.
Square planar divalent complexes of cycloplatinated primary amines can be oxidized in presence of iodine, bromine and methyliodide to octahedral Pt(IV) derivatives. Display omitted
•Square planar Pt(II) complexes and their octahedral Pt(IV) derivatives.•Iodination and bromination of cycloplatinated primary amines.•cis oxidative addition.•Structural characterization of potentially cytostatic compounds.
In the title compound, Pd(C8H10N)(C2H8N2)(C9H9O2), the palladium ion is coordinated in a distorted square-planar fashion by the two N atoms from the chelating ethylenediamine group and by the N and a ...C atom of the deprotonated chiral amine. The resulting cationic complex and the 3,5-dimethylbenzoate anion are interconnected by N—H...O hydrogen bonds.
In the title compound, Pd(C8H10N)(C2H8N2)(C8H7O2)·H2O, the palladium ion is coordinated in a distorted square-planar fashion by the two N atoms from the chelating ethylenediamine group and by ...the N and a C atom of the deprotonated chiral amine. The resulting cationic complex, the 3-methylbenzoate anion and the hydrate water molecule are interconnected by N—H...O and O—H...O hydrogen bonds.
The structure of 3-(3,4-dimethoxyphenylethylamino)-methylidene-1,2,3,9-tetrahydropyrrolo2,1-b-quinazolin-9-one hydrochloride was determined by single-crystal X-ray diffraction at 100 K. The compound ...crystallizes in the monoclinic space group Cc, with a = 4.7149(18), b = 30.075(12), c = 14.199(6) Å, β = 91.852(8)°, Z = 4, V = 2012.4(14) Å
3
. The crystallographic study revealed E configuration of the C11 = N9′ bond. Electrostatic interactions between the organic cation and the chloride anion and classical N-H...Cl hydrogen bonds stabilize this salt. A Hirshfeld surface analysis revealed that H···H, H···C/C···H, and H···O/O···H represent the most prominent Van-der-Waals contacts. For the neutral parent molecule, nuclear magnetic resonance spectroscopy in deuterated chloroform solution showed that two tautomeric forms coexist in 3:1 ratio.
Diffusion reaction of the labile building block Mg(acacCN)
2
(acacCN = 3-cyanoacetylacetonate) with silver salts leads to a series of solvated Mg/Ag bimetallic coordination polymers with composition ...Mg(acacCN)
3
Ag·solvent. Despite their common stoichiometry, the topology of these polymers depends on the solvent of crystallization. The two-dimensional coordination compound Mg(acacCN)
3
Ag·4CHCl
3
in space group
P
1̅ is obtained as platelet-shaped crystals from a mixture of methanol and chloroform. When kept in the reaction mixture, these thin plates within one week convert to isometric tetrahedral crystals of the 3D network Mg(acacCN)
3
Ag·2CHCl
3
in the cubic space group
P
2
1
3. The transformation reaction proceeds via dissolution and recrystallization. The co-crystallized solvent molecules play an important role for stabilizing the target structure: They subtend Cl···Cl contacts and interact via nonclassical C‒H···O hydrogen bonds with the coordination framework. In the new cubic coordination network, both Mg(II) and Ag(I) adopt octahedral coordination, with unprecedented face-sharing by bridging O atoms of three acetylacetonato moieties. Prolonged standing of Mg(acacCN)
3
Ag·2CHCl
3
in the reaction medium leads to further degradation, under formation of Ag(acacCN).
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