Recent developments in the coordination chemistry of selenoether and telluroether ligands

Square planar silver(I) complexes: A rare but increasingly observed stereochemistry for silver(I)

The silver aluminates AgAl[OC(CF3)2(R)]4 (R = H, CH3, CF3) react with solns. of white phosphorus P4 to give complexes that bind one or two almost undistorted tetrahedral P4 mols. in an h2 fashion: [Ag(P4)2]+[Al(OC(CF3)3)4]- (1) contg. the 1st homoleptic metal-phosphorus cation, the mol. species (P4)AgAl[OCMe(CF3)2]4 (2), and the dimeric Ag(m,h2-P4)Ag bridged {(P4)AgAl[OC(H)(CF3)2]4}2 (3). Compds. 1-3 were characterized by variable-temp. (VT) 31P NMR spectroscopy (1 also by VT 31P MAS NMR spectroscopy), Raman spectroscopy, and single-crystal x-ray crystallog. Other Ag:P4 ratios did not lead to new species, and this observation was rationalized on thermodn. grounds. The Ag(P4)2+ ion has an almost planar coordination environment around the Ag+ ion due to dx2-y2(Ag) -> s*(P-P) backbonding. Calcns. (HF-DFT) on six Ag(P4)2+ isomers showed that the planar h2 form is only slightly favored by 5.2 kJ mol-1 over the tetrahedral h2 species; h1-P4 and h3-P4 complexes are less favorable (27-76 kJ mol-1). The bonding of the P4 moiety in [RhCl(h2-P4)(PPh3)2], the only compd. in which an h2 bonding mode of a tetrahedral P4 mol. was claimed, must be regarded as a tetraphosphabicyclobutane, and not as a tetrahedro-P4 complex, from the published NMR and vibrational spectra, the calcd. geometry of [RhCl(P4)(PH3)2] (10), the highly endothermic (385 kJ mol-1) calcd. dissocn. enthalpy of 10 into P4 and RhCl(PH3)2 (11), as well as atoms in mols. (AIM) and natural bond orbital (NBO) population analyses of 10 and the Ag(P4)2+ ion. Therefore, 1-3 are the 1st examples of species contg. h2-coordinated tetrahedral P4 mols. [on SciFinder (R)]

Superweak complexes of tetrahedral P4 molecules with the silver cation of weakly coordinating anions.

Several new Ni (7a−i), Pd (8a−j), and Pt (9a−j) dithiolenes belonging to the general class [M(R,R‘timdt)2] (R,R‘timdt = monoanion of di-substituted imidazolidine-2,4,5-trithione) have been synthesized by sulfuring the disubstituted imidazolidine-2-thione-4,5-diones (4) with Lawesson's reagent (5) in the presence of the appropriate metal either as powder or as chloride. The obtained compounds have been characterized by UV−vis−NIR, FT-IR, and FT-Raman spectroscopies, CP-MAS 13C NMR, and cyclic voltammetry, while [Ni(Me,Pritimdt)2] (7c) was also characterized by X-ray diffraction on a single crystal. Isolation from the reaction mixtures of the complex trans-bis[O-ethyl(4-methoxyphenyl)phosphonodithioato]Ni(II) (10a) and of 4,5,6,7-tetrathiocino[1,2-b:3,4-b‘]diimidazolyl-1,10-diphenyl-3,8-diethyl-2,9-dithione (6a) as byproducts supports a radical mechanism for the one-pot reaction leading to the title dithiolenes. All these complexes absorb in the NIR region in the range 991−1030 nm with extinction coefficien...

New [M(R,R‘timdt)2] Metal-Dithiolenes and Related Compounds (M = Ni, Pd, Pt; R,R‘timdt = Monoanion of Disubstituted Imidazolidine-2,4,5-trithiones): An Experimental and Theoretical Investigation

Coordination chemistry in and of sulfur dioxide

Cyanogen as a Bridging Ligand—Preparation and Crystal Structure of Polymeric [Ag{(CN)2}2]n[AsF6]n with an Undulating Square Cationic Network

Dicyan als Brückenligand ‐ Herstellung und Kristallstruktur von polymerem [Ag{(CN)2}2]n[AsF6]n mit gewelltem quadratischen Netzwerk

The synthesis and structures of silver complexes with trimeric thioformaldehyde and trimeric selenoformaldehyde

The reaction of trimeric thioformaldehyde with AgAsF6 in liquid SO2 leads to the compound [Ag2{(CH2S)3}5][AsF6]2·SO2, which was characterised by X-ray structure determination [space group Pbca, with a= 16.286(3), b= 28.487(5), c= 18.118(3)A, and Z= 8; R= 0.061 for 5 150 unique observed reflections]. The isolated canons, of the form L2AgLAgL2(L = ligand), display irregular co-ordination geometry at silver; one silver is co-ordinated by four sulphurs from three ligands, the other by five sulphurs from three ligands.

Trimeric thioformaldehyde as a ligand: preparation and crystal structure of [Ag2{(CH2S)3}5][AsF6]2·SO2

Die Reaktion der 1,2,5-Selenadiazole 2 und 4 sowie des Bicyclus 6 mit (η2-Ethen)bis(triphenylphosphan)platin(0) fuhrt zu den cyclischen Koordinationsverbindungen (Ph3P)2-PtSeN2(CR)2 (R = CN, 3; R = OCH2CF3, 5) und dem Bicyclus (Ph3P)2PtC4Cl2N4S3 (7). Von 3 wurde eine Rontgenstrukturanalyse angefertigt, die das Vorliegen eines sechsgliedrigen Ringes bestatigt.



Preparation and Structure of New Six-membered Metallaheterocycles – Insertion of Platinum in Selenium-Nitrogen and Sulfur-Nitrogen Bonds



The reaction of 1,2,5-selenadiazoles 2 and 4 and the bicycle 6 with (η2-ethene)bis(triphenylphosphane)platinum(0) leads to the cyclic coordination compounds (Ph3P)2PtSeN2(CR)2 (R = CN, 3; R = OCH2CF3, 5) and the bicycle (Ph3P)2PtC4Cl2N4S3 (7). The structure of 3 was determined by an X-ray structure analysis.

Hartmut Hofmann

Papers

Cyanogen as a Bridging Ligand—Preparation and Crystal Structure of Polymeric [Ag{(CN)2}2]n[AsF6]n with an Undulating Square Cationic Network

Dicyan als Brückenligand ‐ Herstellung und Kristallstruktur von polymerem [Ag{(CN)2}2]n[AsF6]n mit gewelltem quadratischen Netzwerk

The synthesis and structures of silver complexes with trimeric thioformaldehyde and trimeric selenoformaldehyde

Trimeric thioformaldehyde as a ligand: preparation and crystal structure of [Ag2{(CH2S)3}5][AsF6]2·SO2

Darstellung und Struktur neuer sechsgliedriger Metallaheterocyclen – Insertion von Platin in Selen-Stickstoff- und Schwefel-Stickstoff-Bindungen