Novel Dechlorane Analogues and Possible Sources in Peregrine Falcon Eggs and Shark Livers from the Western North Atlantic Regions.

During the investigation of dechlorane-related chemicals in North American wildlife, two unknown polychlorinated compounds (referred to as U1 and U2) were discovered. After extensive sample cleanup, structural information on U1 and U2 was characterized by gas chromatography (GC) coupled with single quadrupole mass spectrometer (MS) or GC-quadrupole time-of-flight (QToF) MS. Mass spectral evidence suggests that both U1 and U2 are structurally related to Dechlorane 603 (Dec603; CHCl), an analogue of the chlorinated flame retardant Dechlorane Plus.

Characterization of Nine Isomers in Commercial Samples of Perfluoroethylcyclohexanesulfonate and of Some Minor Components Including PFOS Isomers.

Electrochemical fluorination of 4-ethylbenzenesulfonyl halides produces a mixture of compounds that has found extensive use as an erosion inhibitor in aircraft hydraulic fluids. This paper reports a study of the composition of commercial samples of this material from two industrial scale manufacturers in terms of the structures and relative concentrations of their components, the major of which is perfluoroethylcyclohexanesulfonate (PFECHS). Fractionation of one of these mixtures by column chromatography produced fractions in which all significant components were of sufficient purity to allow assignment of their structures by F NMR spectroscopy.

Dechlorinated Analogues of Dechlorane Plus.

Degradation products of the chlorinated additive flame retardant Dechlorane Plus (DP) have been discovered globally. However, the identity of many of these species remains unknown due to a lack of available analytical standards, hindering the ability to quantitatively measure the amounts of these compounds in the environment. In the present study, synthetic routes to possible dechlorinated DP derivatives were investigated in an effort to identify the environmentally significant degradation products.

Anion Sensing with a Blue Fluorescent Triarylboron-Functionalized Bisbenzimidazole and Its Bisbenzimidazolium Salt.

A blue fluorescent -dimesitylboryl-phenyl-functionalized 1,3-bisbenzimidazolyl benzene molecule () has been synthesized in high yield by Stille coupling of bisbenzimidazolyl bromobenzene with -BMes-SnBu-benzene. Methylation of led to the formation of the bisbenzimidazolium salt (). The utility of both and in sensing CN and halide (F, Cl, Br, and I) was examined, and it was found that only the small fluoride and cyanide anions were able to bind to the boron atom with binding constants in the range of 2.

Chemistry of the heavy group 15 elements with the pyridyl tethered 1,2-bis(imino)acenaphthene "clamshell" ligand.

Cobaltocene has been used as a one-electron reductant in a facile route to generate pnictogen(I) (P, As) synthons. These subsequently undergo a formal 4 + 2 cycloaddition with a pyridyl tethered 1,2-bis(imino)acenaphthene "clamshell" ligand to yield N-heterocyclic chlorophosphines and -arsines, which are precursors to the corresponding N-heterocyclic pnictenium cations. In the absence of a reductant the "clamshell" ligand can be used in forming hypervalent donor-acceptor complexes with heavy main group elements (Sn, Sb and Bi).

Synthesis, reactivity, and computational analysis of halophosphines supported by dianionic guanidinate ligands.

The reported chemistry and reactivity of guanidinate supported group 15 elements in the +3 oxidation state, particularly phosphorus, is limited when compared to their ubiquity in supporting metallic elements across the periodic table. We have synthesized a series of chlorophosphines utilizing homo- and heteroleptic (dianionic)guanidinates and have completed a comprehensive study of their reactivity. Most notable is the reluctancy of these four-membered rings to form the corresponding N-heterocyclic phosphenium cations, the tendency to chemically and thermally eliminate carbodiimide, and the scarcely observed ring expansion by insertion of a chloro(imino)phosphine into a P-N bond of the P-N-C-N framework.

Electrogenerated chemiluminescence of triazole-modified deoxycytidine analogues in N,N-dimethylformamide.

Triazole-modified deoxycytidines have been prepared for incorporation into single-stranded deoxyribonucleic acid (ssDNA). Electrochemical responses and electrogenerated chemiluminescence (ECL) of these deoxycytidine (dC) analogues, 1-4, were investigated as the monomers. Cyclic voltammetry and differential pulse voltammetry techniques were used to determine the oxidation and reduction potentials of 1-4, along with the reversibility of their electrochemical reactions.

A base-stabilised arsenic(III) dication.

A bulky guanidinate ligand has been utilized in supporting a dichloroarsine, which is an excellent precursor to an arsenium cation and a 2,2'-bipyridine base stabilised arsetidinium dication.

A new approach to internal Lewis pairs featuring a phosphenium acid and a pyridine base.

A bis(imino)acenaphthene (BIAN) ligand containing a pendant Lewis base has been used as a new framework to support a N-heterocyclic phosphenium cation (NHP). Reactivity studies demonstrate the ability of the ligand to act as a Lewis base, while the phosphorus centre provides a Lewis acidic site, giving new opportunities in NHP chemistry.

Blue fluorescent deoxycytidine analogues: convergent synthesis, solid-state and electronic structure, and solvatochromism.

We report the synthesis and photospectroscopic characterisation of intrinsically fluorescent triazole-appended cytidines. Fluorescence was found to be highly dependent on solvent conditions. X-Ray crystallographic data show the proton of the exocyclic amine of the nucleobase and the triazole N(3) engaged in a H-bond.

Chiral, hemilabile palladium(II) complexes of tridentate oxazolidines, including C2-symmetric "pincers".

Two classes of diastereomerically enriched chiral tridentate ligands incorporating either two oxazolidine and one pyridine ( 1) or two pyridine and one oxazolidine ( 2a-c) donor groups have been made in a high-yielding modular fashion from readily available enantiopure amino alcohols and aldehydes. Both ligand classes readily formed metal complexes via 1:1 reactions with trans-PdCl 2(PhCN) 2. The compounds Pd( 1)Cl 2 and Pd( 2a-c)Cl 2 were formed as mixtures of 3 and 2 diastereomers, respectively, owing to indeterminate absolute configuration at the C (2) position of their constituent oxazolidine rings.

Theoretical and experimental investigations of ligand exchange in guanidinate ligand systems for group 13 metals.

The ligand exchange of guanidinate ligands between metal centres can play an important role in guanidinate chemistry, and ligand exchange between aluminium centres will form a dimeric intermediate. The synthesis and characterization of the dimer [Me(2)NC(N(i)Pr)(2)](2)Al(2)Cl(4) is reported here: compound crystallizes with a twisted boat conformation of its dimer ring. This compound decomposes to monomers at room temperature over four days, or within 18 hours at 90 degrees C.

Synthesis and thermolysis of aluminum amidinates: a ligand-exchange route for new mixed-ligand systems.

A novel ligand-exchange route for the synthesis of amidinate-containing compounds of aluminum is explored. Syntheses of three new compounds, MeC(NiPr)2AlEt2 (4), EtC(NiPr)2AlMe2 (5), and (Me2NC(NiPr)2)2AlH (6), are presented. These mixed-ligand compounds are difficult to make in high yields by the more traditional routes of carbodiimide insertion or salt metathesis.