Reduction of acetonitrile by neodymium diiodide: Molecular structure of [{(HNCMe)2MeCNH2}NdI(MeCN)5]I2 and [{(HNCMe)2MeCNH2}Nd(MeCN)6]I3

The reaction of neodymium diiodide NdI₂ (1) with acetonitrile is accompanied by C-C coupling and formation of bis(ethylimine)ethylamine/acetonitrile complexes {[(MeCNH)₂CMeNH₂]NdI(MeCN)₅}I₂ (2) and {[(MeCNH)₂CMeNH₂]Nd(MeCN)₆}I₃ (3). Yields of the products are 9% and 50%, respectively. Probable scheme of the complexes formation is discussed. Treatment of 3 with 2 equiv. of 1 in THF affords NdI₃(THF)₃, hydrogen and monoiodide complex containing presumably bis(imide)amine ligand, NdI[(MeCN)₂CMeNH₂]. The X-ray analysis revealed that in the molecule of 2 one I⁻ anion is directly bonded to Nd³⁺ cation while two other I⁻anions are not in contact to the metal centre. The molecule of 3 is isostructural to previously obtained Dy and Tm analogues. All three I⁻ anions in it are located away from Nd³⁺ cation.     

Preparation, structure, solid state and gas phase stability of the mixed neodymium nitrate-chloride complex NdCl(NO3)2{[(MeO)2PO]2C(OH)Bu}2

The preparation and structure of the mixed anion complex NdCl(NO₃)₂{[(MeO)₂PO]₂C(OH)^tBu}₂ are reported. Single crystal X-ray diffraction shows that the bisphosphonate is bonded via both phosphoryl groups and the nitrates act as bidentate ligands. Intramolecular H-bonding is seen between the OH and the coordinated nitrate and chloride ligands. Thermal decomposition in the solid state is by loss of methyl nitrate. Electrospray mass spectrometry shows that loss of chloride is preferred over loss of nitrate in the gas phase. Attempted preparation of NdCl₂(NO₃){[(MeO)₂PO]₂C(OH)^tBu}₂ leads to the formation of a product approximating to [Nd{^tBu(OH)C(PO₃H₂)₂}₂]₂H · NO₃ · (PO₄H₂)₂. Electrospray mass spectrometry and elemental analysis confirm the presence of the [^tBu(OH)C(PO₄H₂)₂]⁻ in the decomposition products.     

Structure and NIR luminescence of lanthanide(III) complexes with an organic tridentate ligand

Some lanthanide (Ln) complexes (Ln = Er, Nd, Yb) with an organic ligand, 6-diphenylamine carbonyl 2-pyridine carboxylic acid (HDPAP), have been synthesized. The crystal structure and near infrared luminescence of these complexes (Er-DPAP, Nd-DPAP and Yb-DPAP) have been investigated. The results showed that the lanthanide complexes have electroneutral structures and the near infrared (NIR) emission exhibits characteristic narrow emission of the lanthanide ions. The energy transfer mechanisms in the lanthanide complexes were discussed.     

Metal ion interactions with sugars. The crystal structure and FT-IR study of the NdCl3-ribose complex

The single-crystal structure of neodymium chloride-ribopyranose pentahydrate, NdCl3.C5H10O5.5H2O was determined to have Mr=490.80, a=9.138(11), b=8.830(10), c=9.811(11) A, beta=94.087(18) degrees, V=789.7(16) A3, P2(1), Z=2, mu=0.71073 A and R=0.0198 for 2075 observed reflections. The ligand of the title complex was observed in a disordered state and two molecular configurations of NdCl3.C5H10O5.5H2O were found in the single crystal as a pair of isomers. Both ligand moieties of the two molecules are ribopyranose forms, providing three hydroxyl groups in ax-eq-ax orientation for coordination. One ligand of the pair of isomers is beta-D-ribopyranose in the 1C4 conformation, and the other is alpha-D-ribopyranose in the 4C1 conformation. The Nd3+ ion is nine-coordinated with five Nd-O bonds from water molecules, three Nd-O bonds from hydroxyl groups of the ribopyranose and one Nd-Cl bond from chloride ion. The hydroxyl groups, water molecules, chloride ions form an extensive hydrogen-bond network. The IR spectral C-C,O-H,C-O and C-O-H vibrations were observed to be shifted in the complex and the IR results are in accordance with those of X-ray spectroscopy.     

Cubism

The syntheses of [Li₂(salen)(DME)]₂, [Li₂(salpn)(THF)]₂, [Na₂(salpn)(Et₂O)]₂ and [Na₂(salpn)(DME)]₂ (H₂salen = (o-HOC₆H₄CHNCH₂)₂; H₂salpn = (o-HOC₆H₄CHNCH₂)₂CH₂) involve treatment of the appropriate Schiff base with either n-BuLi or MN(SiMe₃)₂ (M = Li, Na) in DME, THF or Et₂O. The X-ray crystal structures of these compounds show that they all have very similar structural motifs comprising M₄O₄ (M = Li or Na) ‘cubanoid’ cores. The synthesis and X-ray crystal structure of [{Nd(salpn)(THF)Cl}{LiCl(THF)}₂]₂ obtained by treatment of [Na₂(salpn)(THF)] with [NdCl₃ · 2(LiCl)] has a dimeric [Nd(salpn)(THF)Cl]₂ molecule sandwiched between two Li₂Cl₂(THF)₂ units.     

Efficient transformation of Serratia marcescens with pBR322 plasmid DNA

Eight Serratia marcescens strains tested could be transformed with the plasmid pBR322. Transformants were selected on the basis of resistance to high levels of ampicillin (400 to 500 micrograms/ml). For six of the strains, the CaCl2- mediated transformation procedure developed for Escherichia coli was successful. For the other two strains, no transformants were obtained with the CaCl2-mediated transformation procedure unless the cells first received a heat treatment. Transformation frequency was dependent on DNA concentration, and no transformation was detected with linear pBR322 DNA. The stability and copy number of pBR322 were similar in S. marcescens and E. coli. As in E. coli, the pBR322 DNA was amplified in S. marcescens after inhibition of proteins synthesis. Based on these results, cloning in S. marcescens should be possible and pBR322 should be a useful cloning vehicle.     

Sugar complexes with neodymium nitrate. Spectroscopic and structural studies of two Nd(NO3)3-galactitol complexes

Two different Nd(NO3)3-galactitol complexes, 2Nd(NO3)3.C6H14O6.8 H2O and Nd(NO3)3.C6H14O6 have been obtained and were characterized by FT-IR and X-ray diffraction techniques. The spectral differences of the two complexes were consistent with the crystal-structure data.     

Synthesis of a C-linked hyaluronic acid disaccharide mimetic

The synthesis of a C-disaccharide that is designed as a mimetic for the repeating unit disaccharide of hyaluronic acid is described. The target compound was obtained via the SmI2-promoted coupling reaction of the sulfone, 2-acetamido-4,6-O-benzylidene-3-O-tert-butyldimethylsilyl-1,2-dideoxy-1-pyridinylsulfonyl-beta-D-glucopyranose (6), and the aldehyde, p-methoxyphenyl 2,3-di-O-benzyl-4-deoxy-4-C-formyl-6-O-p-methoxybenzyl-beta-D-glucopyranoside (14).