A chiral, heterometallic metal-organic framework derived from a tris(chelate) coordination complex

A novel tris(chelate) metalloligand has been used to synthesize a chiral, heterometallic metal-organic framework that is robust to solvent removal and shows selective uptake of nitroaromatic compounds.     

Characterization of dimeric chiral lithium amide structures derived from N-isopropyl-O- triisopropylsilyl valinol

The dimeric structure is characterized for a chiral amide base complex consisting of an (S)-N-isopropyl-O-triisopropylsilyl valinol ligand and lithium. The complex is characterized by a variety of NMR techniques, including multinuclear one- and two-dimensional NMR experiments and diffusion-ordered NMR spectroscopy (DOSY) as well as diffusion coefficient-formula weight (D-fw) correlation analyses. Spartan calculations are presented which support the structural assignment. This structural characterization leads to an explanation of the behavior and the reactivity of these complexes in solution.     

The chemistry of (1-azabuta-1,3-diene)tricarbonyliron(0) complexes

In this review, an overview of synthetic and structural aspects of 1-azabuta-1,3-diene complexes of iron is given and the reactivity of these complexes is discussed with regard to inorganic, organometallic, organic and stereochemical aspects of their chemistry. Their application in the synthesis of organic and organometallic target compounds, or as transfer reagents of the tricarbonlyiron(0) moiety is demonstrated.     

Sulfur-bridged dimers obtained from μ-dithiobis(tricarbonyliron)

The reaction of SO₂Cl₂ with (μ-MS)(μ-ArS)Fe₂(CO)₆ (M = Li; Ar = Ph and M = MgBr; Ar = p-tolyl) results in oxidation of the latter and formation of SS bonded “dimers”. The “dimer” where Ar = Ph crystallizes in the space group P$\text{1}$ with a 10.584(4), b 11.247(1), c 14.275(3) Å, α 104.20(2), β 90.80(4), γ 98.12(2)°, V 1629 ų and Z = 2. Full matrix least-squares refinement yields a final R value of 4.4% based on 3986 independent reflections. The central SS bond is longer than that in elemental sulfur or in (μ-S₂)Fe₂(CO)₆.     

Synthesis of chiral aza-bis(oxazolines) derived from (+)-camphor

Two novel chiral structurally azabis(oxazoline) ligands were synthesized using (+)-camphor as the starting material. Each of the ligands was prepared through the corresponding aminoalcohols. The structures of some crystalline derivatives were unambiguously established by X-ray analysis.     

New iron complexes from nucleophile addition/carbonylation of η4-(1,3-diene)tricarbonyliron(0) complexes

A series of novel organoiron complexes has been isolated and studied by ¹H NMR, ¹³C NMR, and IR spectroscopy. Addition of LiC(CH₃)₂CN to (1,3-cyclohexadiene)tricarbonyliron produces an intermediate which is only stable at low temperature and which is assigned the homoallyl—Fe(CO)₃ anion structure. The intermediate rearranges on warming into a stable complex, for which full spectral data support the structure as an allyl—Fe(CO)₃ anionic species. Interception of the first formed intermediate with CO gives an acylferrate complex with an olefin unit still bound to iron, and methylation then occurs at oxygen to produce an unusual internally-bound (alkene)(methoxyalkylidene)tricarbonyliron species.     

Structure and properties of an Fe(III) complex containing a novel amide functionalized polyimidazole ligand

A novel amide functionalized polyimidazole tripod ligand has been synthesized and used to prepare a mononuclear Fe(III) complex that has been characterized by X-ray crystallography and other physical methods.     

Linear poly(amide triazole)s derived from d‐glucose

The click reaction between azides and alkynes is been increasingly employed in the preparation of polymers. In this article, we describe the synthesis and click polyaddition reaction of a new A‐B‐type amide monomer—prepared from d ‐glucose as renewable resource—containing the alkyne and azide functions. Both Cu(I)‐catalyzed and metal‐free click polymerization methods were used to prepare glucose‐derived poly(amide triazole)s. The resulting polymers had weight‐average molecular weights in the 45,000–129,000 range and were characterized by GPC, IR, and NMR spectroscopies. Thermal and X‐ray diffraction studies revealed them to be amorphous. Their qualitative solubilities in various solvents and their water sorption have been studied. The poly(amide triazole)s having the alcohol functions protected as methyl ether were water‐soluble. The presence of the amide functions along the polymer chain made these polytriazoles degradable in the presence of sodium deuteroxide. The degradation was monitored by NMR analysis, and the degradation product was characterized by HRMS. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 629–638     

Synthesis and structure of a chiral dinuclear palladium(0) complex with a 30-membered hexaolefinic macrocyclic ligand

Selective and efficient preparation of a new chiral dipalladium(0) complex with an olefinic macrocyclic ligand named (E,E,E,E,E,E)-1,6,11,16,21,26-hexakis[(4-methylphenyl)sulfonyl]-1,6,11,16,21,26-hexaazacyclotriaconta-3,8,13,18,23,28-hexaenedipalladium(0) (5) is reported. Dinuclear palladium(0) complex 5 has been fully characterized by means of NMR spectroscopy and X-ray diffraction analysis.     

Synthesis and characterization of a family of biodegradable poly(ester amide)s derived from glycine

A series of aliphatic poly(ester amide)s derived from 1,6-hexanediol, glycine, and diacids with a variable number of methylenes (from 2 to 8) have been synthesized and characterized. Infrared spectroscopy shows that the studied polymers present a unique kind of hydrogen bond that is established between their amide groups. Thermal properties as melting, glass transition, and decomposition temperatures are reported. The data indicate that all the polymers are highly crystalline. Thus, different kinds of spherulites (positive and/or negative) were obtained depending on the preparation conditions and on the polymer samples. Moreover, all the polymers crystallized from dilute diol solutions as ribbonlike crystals where a regular folding habit and a single hydrogen bond direction could be deduced. A test of enzymatic hydrolysis was employed to assess the potential biodegradability of these polymers. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1271–1282, 1998