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The synthesis and characterization of a series of cyclometallated complexes of Pd(ii) incorporating the mixed donor ligand 1-oxa-4,7-dithiacyclononane ([9]aneS2O) are presented in this study. Complexes of the form [Pd(C^N)([9]aneS2O)](PF6) (C^N = 2-phenylpyridine (ppy) 1b, 4-(2-pyridyl)benzaldehyde (ppyCHO) 2b, 7,8-benzoquinoline (bzq) 3b, 2-benzothienylpyridine (btp) 4b, 2-phenylbenzothiazole (pbt) 5b), were obtained in high-yield from a simple two-step synthetic scheme. All of these complexes were fully characterized by NMR, ESI-MS, IR, combustion analyses, and most (1b, 2b, 4b, 5b) by X-ray crystallography. Solution 1H and 13C NMR studies of [Pd(C^N)([9]aneS2O)](PF6) complexes demonstrate complicated [9]aneS2O behavior at room temperature. Variable temperature NMR reveals dynamic bonding of the [9]aneS2O ligand consistent with the presence of both endodentate and exodentate bonding modes. This is in stark contrast to the related [9]aneS3 (1,4,7-trithiacyclononane) cogeners that demonstrate fluxional endodentate bonding only in solution. X-ray structures reveal only exodenate [9]aneS2O bonding in this series, unlike the related [9]aneS3 complexes that show endodenate bonding with an axial Pd…S interaction. DFT calculations performed on endo and exo [9]aneS2O bonding forms of 4b, as well as a transition state calculation for interconversion, suggest reasonable access to both bonding forms based on the energy barrier. Natural bond order calculations provide further evidence for a weak axial Pd…O interaction in the endo form of 4b. [ABSTRACT FROM AUTHOR]

Abstract: We wish to report the synthesis of the Ru(II) crown thioether complex, (1,4,7,10,13-pentathiacyclopentadecane)chlororuthenium(II) hexafluorophosphate, [Ru([15]aneS5)Cl](PF6), and a study of its properties utilizing single crystal X-ray diffraction, electronic spectroscopy, NMR spectroscopy, density functional theory calculations and cyclic voltammetry. The crystal structure shows a single [15]aneS5 macrocycle and a chloro ligand coordinated in a distorted octahedral fashion around the ruthenium(II) center. A significant shortening (0.15Å) of the trans Ru–S bond length occurs in this complex compared to the related PPh3 complex (2.4458(10) to 2.283(1)Å) due to the differences in the trans influence of the two ligands. 13C NMR spectroscopy demonstrates that the structure of [Ru([15]aneS5)Cl]+ is retained in solution. As expected for a Ru(II) complex, the electronic absorption spectrum shows two d–d transitions at 402 and 331nm. These are red-shifted compared to hexakis(thioether)ruthenium(II) complexes and consistent with the weaker ligand field effect of the chloro ligand. The electrochemical behavior of the complex in acetonitrile shows a single one-electron reversible oxidation–reduction at +0.722V versus Fc/Fc+ which is assigned as the Ru(II)/Ru(III) couple. DFT calculations for [Ru([15]aneS5)Cl]+ show a HOMO with orbital contributions from a t 2 g type orbital of the Ru ion, a π component from a p orbital of the axial S atom of [15]aneS5, and a p orbital of the chloro ligand while the LUMO consists of orbital contributions of orbital of the Ru center and p orbitals of the four equatorial S donors. [ABSTRACT FROM AUTHOR]

Examines the synthesis of potassium 2,2'-bipyridinetetranitroruthenate compound. Importance of the thermal displacement of benzene for the completion of the synthesis; Application of X-ray crystallography for the analysis; Evaluation of the crystal structure of the compound.

Monoanionic N 2 P 2 beta-diketiminate (BDI) ligands with phosphine pendant arms were prepared and metallated with zinc(II) iodide. With a goal of understanding the ligands' sterics, methyl and methoyx substituents were introduced on the phenyl linkers. Two different binding modes were observed based on the presence of a substituent at position 6. [Display omitted] Monoanionic mixed N 2 P 2 donor beta-diketiminate (BDI) ligands with phosphine pendant arms, 2-(4-tolyl)-bis(2-diisopropylphosphinophenyl)propenediimine (abbreviated as Tol-BDI(DIPPP)2H), were prepared and metallated with zinc(II) iodide. Three ligand variations have been synthesized by incorporating different substituents (methyl or methoxy) on the linker phenyl rings at positions 4 and 6. In the 4-methyl zinc complex [Tol-BDI(DIPPMeP)2ZnI] and 4-methoxy zinc complex [Tol-BDI(DIPPMeOP)2ZnI], the metal is bound to all four donors on the ligand, rendering a distorted square pyramidal geometry around the zinc metal with τ 5 values of 0.25 and 0.29, respectively. However, the crystal structure of the 4,6-dimethyl zinc complex [Tol-BDI(DIPPMe2P)2ZnI] shows a four-coordinate zinc with only one phosphine bound to the metal, resulting in a distorted seesaw geometry around the metal. While X-ray crystallography shows no interactions between the metal center and the unbound phosphine, solution characterization reveals a symmetrical complex with both phosphines bound to the metal center in all three zinc complexes. [ABSTRACT FROM AUTHOR]