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The UV-vis -NIR photoluminesccence and FT-IR techniques are implemented to study the physicochemical properties of 5-aza[5]helicene (H5) in solutions of ytterbium bis(2-ethlhexyl) sulfosuccinate reversed micelles. The insertion of dissolved H5 in the micelles leads to a one-dimensional growth of reversed micelles

The computations on the ] system is presented in order to clarify the structures of its two known isomers. The computations have indicated that the major species should have the isolated pentagon rule (IPR) cage, while the minor one should contain one pentagon-pentagon junction in the carbon cage.

Three [beta]-diketonate complexes of erbium and ytterbium are synthesized and structurally characterized and their luminescent properties are examined. Compared with monometallic complexes, the stoichiometrically cocrystalline complex exhibits special indirect near-infrared luminescence with the acceptor and senistizer coexisting in a single crystal.

Significant rate acceleration of metal-catalyzed Michael addition reactions in water is observed upon addition of small, dibasic ligands. Ytterbium triflate and TMEDA is the most effective combination leading to a nearly 20-fold faster reaction than in the absence of ligand.

The first unsolvated metal(II) aryls of the rare-earth metals europium and ytterbium are prepared and structurally characterized, supported by a very bulky aryl-substituted triazenide ligand. In the solid state and in solution, kinetic stabilization through steric and electronic saturation of metal centers is achieved by additional pi-arene interactions to the pendent aryl substituents.

Raman spectroscopic study of [Pb(sub 1-x)Ba(sub x)](Yb(sub 1/2)Ta(sub 1/2)]O3 ceramics, x = 0.0, 0.2, 0.25, 0.2, 0.3 and 1.0, combined with x-ray diffraction analysis and dielectric constant measurements are reported. The quantitative analysis shows that the substitution of Ba for Pb leads to a decrease in the degree of ordering and occurrence of local distortions in the lattice as seen by the broadening of certain peaks in the Raman spectra.

M-H-B bridges and M...alpha-H-C agostic interactions with Eu(II), Yb(II), and K cations occur in a series of 9-BBN hydroborate, [H(sub2)BC(sub8)H(sub14)](super -), complexes. The preparation, the structural and the spectroscopic characterization of Eu(II) and Yb(II) 9-BBN hydroborates is reported.

The prevalent belief about a strong anisotropy of the magnetic exchange in rare-earth compounds, Cs3-Yb2Cl9 and Cs3Yb2Br9 crystals are found to exhibit fully isotropic exchange coupling between Yb(super 3+) ions. An attempt is made to reveal the physical origin of this surprising feature.

Dinuclear complexes are prepared in which a Pt(super II)-(NN)-diacetylide or Re(super 1)(NN)(CO)(sub 3)Cl chromophore is connected to a lanthanide tris luminophore via bipyrimidine as a bridging ligand. The d-block units thus act as light-harvesting components to achieve sensitized near-infrared luminescence from the lanthanide unit.

The nature of the ternary complexes formed in aqueous media at ambient pH on reversible binding of acetate, lactate, citrate, and selected amino acids and peptides to chiral diaqua europium, gadolinium, or ytterbium cationic complexes is examined. The polarizability of the axial donor plays the dominant role in determining the magnetic anisotropy factor that defines the spectral form and dipolar NMR shift of these monocapped square antiprismatic Eu and Yb complexes.

The structure of the Yb3+ ion is studied in aqueous solutions at up to 500 degrees C and 270 MPa. The rate of reduction of the Yb3+ aquo ion is examined.

The development of a novel mixed lanthanide-transition-metal based supramolecular self-assemblies that were made from neodymium and ytterbium-based tetraamide-functionalized cyclen complexes bearing a single 1,10-phenanthroline moiety coordinating to a [Ru.sub.II][(bipy).sub.2] (bipy = bipyridine) unit is presented. It is seen that the excitation of the Ru(II) metal-to-ligand charge-transfer band in water gave rise to long-wavelength sensitized emission from the Yb(III) or Nd(III) centers, observed in the near-infrared.

Aldimines, generated in situ by the reaction of primary amines or anilines with aldehydes, undergo smooth reaction with various 1,1-cyclopropanediesters in the presence of catalytic Yb(OTf)3. The products are pyrrolidines in which the major diastereomer bears a cis relationship between substituents at the 2- and 5-positions.

A study was conducted to establish multiconfigurational, intermediate valent ground states in several methyl-substituted bipyridine complexes of bis(pentamethylcyclopentadienyl)ytterbium, [Cp.sub.2]*Yb ([Me.sub.x]-bipy). In contrast to [Cp.sub.2]*Yb(bipy) and other substituted-bipy complexes, the nature of both the ground state and the first excited state could be altered by changing the position of the methyl or dimethyl substitutions on the bipyridine rings.

Two series of deuterated cryptates with the lanthanoids Yb and Nd are prepared and the luminescent lifetimes for the corresponding near-IR emission bands are measured. Global fitting of the lifetime data combined with structural analysis has helped in the accurate quantification of the contributions of individual C-H oscillators groups in the ligand to the nonradiative deactivation rates of the emissive lanthanoid states.

The anion-exchangeable framework hydroxide ([Yb.sub.3]O[(OH).sub.6]Cl.2[H.sub.2]O) is prepared hydrothermally. The framework is thermally stable below 200 [degree]C, it can be reversibly dehydrated and rehydrated with no loss of crystallinity and it undergoes anion-exchange reactions with small ions such as carbonate, oxalate and succinate with retention of the framework structure.

The synthesis and isolation of a series of [super 13]C 'enriched monoytterbium endohedral metallofullerenes (EMFs), ] (n = 40, 41, 42), are described. The studies have shown that all isomers of ] (n = 40, 41, 42) has displayed one or two reversible oxidation steps together with four reversible reduction processes in 1,2-dichlorobenzene, even at a low scan rate, which has enabled the estimation of their electrochemical bandgaps.

The article presents a newly developed simple and low-cost hydrothermal method, which can be employed for the synthesis of the ytterbium silicate nanoparticles. The results demonstrate the exhibition of low thermal conductivity and high structural stability of the compounds.

The article explains the thermodynamics, as well as the kinetics that are involved in the reactions of various different lanthanides, actinides and transition- and heavy-metal cations. The mechanisms associated with the complexation reactions of these compounds are also discussed.

The article discusses a new approach, which can be used for an effective multiphoton upconversion of the rare earth oxide powders via the help of infrared laser diodes. The methodology is shown to be extremely accurate and effective.

The article explains a new strategy that can be employed for the orthogonal activation of propargyl and n-pentenyl glycoside s. The approach is shown to be effective for the activation of various orthoesters as well.

The synthesis of [n,5]-spiroketals (n = 5, 6) via use of exocyclic enol ethers as starting materials is reported. Addition of catalytic amounts of the Lewis acid [Yb(OTf).sub.3] is observed to facilitate the ring enlargement and increase the yield of the corresponding spiroketal in many synthesis examples.

Spectroscopy and crystallography are used for determining the divalent calcium and ytterbium compounds M[(C[(SiH[Me.sub.2]).sub.3]).sub.2][THF.sub.2] contain [beta]-agostic SiH groups. [beta]-Elimination is not an observed reaction pathway despite the strong hydridic character of the SiH groups and the low-coordinate, Lewis acid metal center in M[(C[(SiH[Me.sub.2]).sub.3][THF.sub.3] compounds.

A facile wet chemical technology was used to prepare monoMonodispersed Ca[F.sub.2]:[Yb.sup.3+]/[Er.sup.3+] nanocrystals. The results from the comparison of upconversion luminescence properties of Ca[F.sub.2]:[Yb.sup.3+]/[Er.sup.3+] nanocrystals with those of NaY[F.sub.4]:[Yb.sup.3+]/[Er.sup.3+] nanocrystals indicated potential use of Ca[F.sub.2] as a promising host material for producing desirable upconversion luminescence.

The application of ytterbium triflate as an efficient catalyst for addition of amines to carbodiimides to N,N',N'-trisubstituted guanidines is described. The reaction is demonstrated the wide scope of amines under solvent-free condition.

A new heterobimetallic Ga[(O-iPr).sub.3]/Yb[(OTf).sub.3]/Schiff base complex is developed for catalytic asymmetric [alpha]-additions of isocyanides to aldehydes. The Ga[(O-iPr).sub.3]/Yb[(OTf).sub.3]/Schiff base complex has promoted asymmetric [alpha]-additions of [alpha]-isocyanoacetamides to aryl, heteroaryl, alkenyl, and alkyl aldehydes in excellent enantioselectivity.

The data obtained for ytterbium valence measurements were used to establish the partial ytterbium f-orbital occupancy and open-shell singlet formation of a variety of bipyridine and diazabutadiene adducts with decamethylytterbocene, [([C.sub.5][Me.sub.5]).sub.2]Yb, abbreviated as [Cp*.sub.2]Yb. The results obtained have significant implication to understand the chemical bonds in organolanthanide complexes and f-element chemistry as well as magnetic interactions in nanoparticles and devices.

Ytterbium(III) triflate-catalyzed ring opening of substituted 1-cyclopropyl-2-propyn-1-ols with sulfonamdies as an efficient route to conjugated enynes is described. The reaction is operationally straightforward and is accomplished in regioselective manner in all except one case under mild conditions.