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Research has been conducted on the cationic palladium complexes. The X-ray structures of these complexes have been investigated and discussed.

The bicyclo[2.1.1]hexane moiety of solanoeclepin A is synthesized by an intramolecular [2+2] photocycloaddition starting with aldehyde containing the dioxenone chromophore. Photolysis of the unsubstituted alkene yields crossed cycloaddut bicyclo[2.1.1]hexane.

Research describes the preparation of a series of novel phosphine-phosphite ligands containing a chiral phosphine moiety, which serve as ligands in the palladium catalyzed allylic alkylation reactions. The reaction of diphenyl-2-propenyl acetate with dimethyl malonate, mediated by these ligands exhibits good enantioselectivities.

The inorganometallic complex Ru(SnPh3)2(CO)2(iPr-DAB), where iPr-DAB = N,N'-diisopropyl-1,4-diaza-1,3-butadiene, is synthesized and subjected to UV-vis, IR, 1H NMR, 13C NMR, 119Sn NMR and mass (FAB+) spectroscopy and X-ray diffraction. The complex has two trans Ru-Sn sigma-bonds which determine its bonding properties. It also has a delocalized 3-center, 4-electron Sn-Ru-Sn sigma-bond, a highly mixed Ru-d(pi), Ru-5pz, Sn-sp3, and DAB-pi* characters in the highest occupied molecular orbital and the lowest unoccupied MO, and undergoes one-electron reduction to a radical anion.

The alcoholysis of a variety of acetylpalladium complexes is studied and found that cis-coordination of alcohol and acetyl is needed to form an ester. The outer -sphere attack of alkoxides/alcohols is not viable mechanism for alcoholysis.

The electronic effect in the rhodium diphosphine catalyzed hydroformylation was studied by synthesizing a series of electronically modified thixantphos ligands. The effects of the ligands on coordination chemistry and catalytic performance were also investigated. Experimental results showed that the (diphosphine)Rh(CO)2H compounds contain dynamic equilibria of diequatorial and equatorial-apical isomers. It was concluded that the chelation mode in the (diphosphine)Rh(CO)2H compounds does not necessarily play a key role in controlling the regioselectivity for linear aldehyde formation.

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The title compound, C11H17N2O3PS2, is a cyclic thio­phos­phoryl pyrimidine derivative exhibiting insecticidal properties. The crystal structure determination gives evidence for the presence of the thione isomer of the compound. The pyrimidine nucleus is planar and its substituents have small deviations from the least-squares plane. The dioxaphos­phorinane ring adopts a chair conformation. The lack of classical hydrogen bonds and the weak intermolecular interactions lead to a `loose' packing characterized by channels in the structure. [ABSTRACT FROM AUTHOR]

Several novel rhodium allyl complexes have been prepared and their structures have been studied using NMR spectroscopy and X-ray crystallography. Depending on the bite angle of the ligand and the substitution pattern of the allyl group, two different coordination modes (η1 and η3) have been observed for the allyl moiety. The activities of these Rh allyl complexes in the allylic alkylation reaction have been tested. We have shown that both coordination modes give active complexes in this reaction, but that the regioselectivity is dependent on the coordination mode of the allyl group. [Copyright &y& Elsevier]

In 3-methyl­anilinium picrate (3-MAP), C7H10N+·C6H2N3O7−, one of the nitro groups in the picrate ion is rotationally disordered with site occupancy factors of 0.80 and 0.20. The expected proton transfer took place between picric acid and 3-methyl­aniline, and the amine group is hydrogen bonded to two of the phenolate O atoms. The ortho-nitro groups deviate greatly from the benzene plane of the picrate ion, facilitating hydrogen-bond formation. While the cations are stacked as columns along the [001] direction, the anions are stacked in an offset fashion. [ABSTRACT FROM AUTHOR]

In the structure of the title compound, 2C5H7N2+·SO42−, the S atom of the sulfate anion lies on a twofold axis. The structure is stabilized by an extensive network of N—H⋯O hydrogen bonds. [ABSTRACT FROM AUTHOR]

In the title complex, C5H16N22+·2C6H2N3O7−, the two picrate anions lie almost parallel to each other and have possible π–π inter­actions between them. One of the anions is involved in limited N—H⋯O bonds, whereas the other engages in extensive N—H⋯O and C—H⋯O hydrogen bonds. Tilting of one of the ortho nitro groups in the picrate anion is influenced by the N—H⋯O hydrogen bond. The dimethyl­aminopropyl­ammonium and picrate ions are linked through N—H⋯O and C—H⋯O hydrogen bonds, forming chains along the crystallographic b axis. The anions form near-helical columns along the b axis owing to the presence of a 21 screw and are separated by nearly linear cationic chains. [ABSTRACT FROM AUTHOR]

The title mol­ecular complex, C25H25BrF3N4+·C6H2N3O7−, crystallizes with two pairs of cations and anions in the asymmetric unit. While the orientations of the two cations are nearly parallel to one another, this is not so for the anions. The imidazonaphthyridine moiety is planar and the methyl­piperidine group is approximately perpendicular to it and adopts an ideal chair conformation. The planes of the bromo­phen­yl rings deviate from the planes of the imidazonaphthyridine moieties by 30.2 (2) and 22.6 (3)° in the two cations, making a marked difference in the overall conformation of the cations. The N—H⋯N hydrogen bond forms an intra­molecular ring pattern S(7) in both cations. The anions and cations are connected through N—H⋯O, C—H⋯O and C—H⋯F hydrogen bonds. [ABSTRACT FROM AUTHOR]

The title salt, C6H16N+·C6H2N3O7−, crystallizes with two pairs of cations and anions in the asymmetric unit. Anions A and B are stacked alternately in the (020) plane to form anionic columns having an ABABAB... sequence, with possible π–π inter­actions between them. The cationic columns surround these columns in an almost hexa­gonal fashion, with each column of the same type of cation, A or B. The anions and cations are connected through lone N—H⋯O and by other C—H⋯O hydrogen bonds. N—H⋯O and C—H⋯O hydrogen bonds involving A-and B- type ions form a cyclic pattern with a graph-set descriptor R22(10). [ABSTRACT FROM AUTHOR]

In the title salt, C21H23N4+·C6H2N3O7−·H2O, the dimethyl­ammonio­methyl side chain is oriented nearly perpendicular to the imidazonaphthyridine moiety, which is nearly planar. In the crystal structure, inter­molecular N—H⋯O and O—H⋯O hydrogen bonds link two cations, two anions and two water mol­ecules into clusters, which further inter­act via weak C—H⋯O hydrogen bonds. [ABSTRACT FROM AUTHOR]

In the title salt, C2H8N+·C6H2N3O7−, there is complete transfer of the OH proton from picric acid to the amine. The picrate anions lie almost parallel to the monoclinic (101) plane and are connected by O⋯O short contacts. The ethyl­aminium and picrate ions are linked through N—H⋯O and C—H⋯O hydrogen bonds along the crystallographic b axis. In the picrate anion, tilting of the para-nitro group is a consequence of C—H⋯O hydrogen bonding between the ions. [ABSTRACT FROM AUTHOR]

Four furanoditerpenoids were isolated from roots of Croton jatrophoides (Euphorbiaceae) collected in Tanzania. In addition to the known compounds penduliflaworosin and teucvin (mallotucin A), a new teucvin isomer, which was named isoteucvin, and a furanoditerpenoid with a new skeleton, for which the name jatrophoidin was adopted, were isolated. Their structures were elucidated by spectroscopic methods such as ESI-MS and NMR, including (1)H-, (13)C-, and two-dimensional NMR. The crystal structures of isoteucvin and jatrophoidin were solved using single-crystal X-ray diffraction, by which we also established the absolute configuration of jatrophoidin. The refined crystal structure of isoteucvin has the same (absolute) configuration as jatrophoidin, although the X-ray diffraction data of isoteucvin were not conclusive with respect to the absolute configuration.

The compact tricyclic substructure of solanoeclepin A containing the cyclobutanone ring was prepared by using as the key step a highly regioselective intramolecular [2 + 2]-photocycloaddition reaction between one of the [small pi]-bonds of an allene and the CC double bond of a butenolide.

Ru(SnPh(3))(2)(CO)(2)(iPr-DAB) was synthesized and characterized by UV-vis, IR, (1)H NMR, (13)C NMR, (119)Sn NMR, and mass (FAB(+)) spectroscopies and by single-crystal X-ray diffraction, which proved the presence of a nearly linear Sn-Ru-Sn unit. Crystals of Ru(SnPh(3))(2)(CO)(2)(iPr-DAB).3.5C(6)H(6) form in the triclinic space group P&onemacr; in a unit cell of dimensions a = 11.662(6) Å, b = 13.902(3) Å, c = 19.643(2) Å, alpha = 71.24(2) degrees, beta = 86.91(4) degrees, gamma = 77.89(3) degrees, and V = 2946(3) Å(3). One-electron reduction of Ru(SnPh(3))(2)(CO)(2)(iPr-DAB) produces the stable radical-anion [Ru(SnPh(3))(2)(CO)(2)(iPr-DAB)](*-) that was characterized by IR, and UV-vis spectroelectrochemistry. Its EPR spectrum shows a signal at g = 1.9960 with well resolved Sn, Ru, and iPr-DAB (H, N) hyperfine couplings. DFT-MO calculations on the model compound Ru(SnH(3))(2)(CO)(2)(H-DAB) reveal that the HOMO is mainly of sigma(Sn-Ru-Sn) character mixed strongly with the lowest pi orbital of the H-DAB ligand. The LUMO (SOMO in the reduced complex) should be viewed as predominantly pi(H-DAB) with an admixture of the sigma(Sn-Ru-Sn) orbital. Accordingly, the lowest-energy absorption band of the neutral species will mainly belong to the sigma(Sn-Ru-Sn)-->pi(iPr-DAB) charge transfer transition. The intrinsic strength of the Ru-Sn bond and the delocalized character of the three-center four-electron Sn-Ru-Sn sigma-bond account for the inherent stability of the radical anion.