The enantiomerically pure dibromoferrocene 3 [(Sp,Sp )-1,1'-dibromo-2,2'-di(isopropyl)ferrocene], equipped with two iPr groups in α positions, was prepared using known "Ugi amine" chemistry. Species 3 was targeted in order to gain access to new [1]ferrocenophanes ([1]FCPs) to be used as monomers for ring-opening polymerization. The iPr groups on the sandwich unit were introduced to stabilize bridging moieties, as well as to increase solubilities of targeted metallopolymers. The planar chiral dibromide 3 can quantitatively be lithiated at 0°C [2 equiv nBuLi, hexanes/thf (9:1), 30 min]. Salt-metathesis reactions with respective element dichloride species gave chiral [1]FCPs with a variety of bridging moieties [ERx =Ga[2-(Me2NCH2)C6H4] (4 a), SiMe2 (4 b), SntBu2 (4 c), BNiPr2 (4 d)]. The new [1]FCPs were fully characterized including single-crystal X-ray analysis. The stabilizing iPr groups on the Cp rings increase the thermal stabilities of 4 b-d compared to known [1]FCPs, equipped with the same bridging moieties. All three compounds 4 b-d are volatile and could be isolated by vacuum sublimation. Our new approach to [1]FCPs has the potential to overcome many of the existing difficulties in ferrocenophane chemistry, such as limited stability of starting monomers and low solubilities of resulting polyferrocenes.

The reaction of SeCl2 with tert-butylamine in various molar ratios in THF at -78 degrees C has been investigated by 77Se NMR spectroscopy. In addition to the known Se-N heterocycles Se6(NtBu)2 (1) and Se9(NtBu)6 (2), the acyclic imidoselenium(II) dichlorides ClSe[N(tBu)Se]nCl (4, n = 1; 5, n = 2) and two new cyclic selenium imides [Se3(NtBu)2]n (3, n = 1 or 2) and Se3(NtBu)3 (6) have been isolated and identified. An X-ray analysis shows that 6 is a six-membered ring in a chair conformation with magnitude of d(Se-N) = 1.833 A. Crystal data: 6, trigonal, P3c1, a = 9.8660(3) A, c = 20.8427(7) A, V = 1757.0(1) A3, Z = 6. The 1H, 13C, and 77Se NMR data for 1-6 are reported, and some reassignments of earlier literature data for 1-3 (n = 1) are made. The decomposition of tBuN=Se=NtBu at 20 degrees C in toluene was monitored by 77Se NMR. The major products are 6 and 3. The Se(IV)-N systems tBuNSe(mu-NtBu)2E (7, E = SO2; 8, E = SeO) were prepared by the reaction of a mixture of SeCl4 and excess tBuNH2 with SO2Cl2 or SeOCl2, respectively. Compound 8 is also generated by the cycloaddition reaction of tBuNSeNtBu with tBuNSeO. Both 7 and 8 consist of slightly puckered four-membered rings. The mean terminal and bridging Se-N distances in 7 are 1.665(2) and 1.948(2) A, respectively. The corresponding values for 8 are 1.687(4) and 1.900(4) A, and d(Se=O) = 1.628(4) A. Crystal data: 7, monoclinic, P2(1)/c, a = 18.669(4) A, b = 12.329(2) A, c = 16.463(3) A, beta = 115.56(3) degrees, V = 3418.4(11) A3, Z = 4; 8, triclinic, P1, a = 6.372(1) A, b = 9.926(2) A, c = 14.034(3) A, alpha = 99.320(3) A, beta = 95.764(3) A, gamma = 103.876(3) A, V = 841.3(3) A3, Z = 2.

Herein, we describe the synthesis of a toroidal Au 10 cluster stabilized by N -heterocyclic carbene and halide ligands via reduction of the corresponding NHC–Au–X complexes (X = Cl, Br, I). The significant effect of the halide ligands on the formation, stability, and further conversions of these clusters is presented. While solutions of the chloride derivatives of Au 10 show no change even upon heating, the bromide derivative readily undergoes conversion to form a biicosahedral Au 25 cluster at room temperature. For the iodide derivative, the formation of a significant amount of Au 25 was observed even upon the reduction of NHC–Au–I. The isolated bromide derivative of the Au 25 cluster displays a relatively high ( ca . 15%) photoluminescence quantum yield, attributed to the high rigidity of the cluster, which is enforced by multiple CH−π interactions within the molecular structure. Density functional theory computations are used to characterize the electronic structure and optical absorption of the Au 10 cluster. 13 C-Labeling is employed to assist with characterization of the products and to observe their conversions by NMR spectroscopy.

The high-yield synthesis, spectroscopic and structural determination of three new uranium(IV) and thorium(IV)ate complexes supported by three different diamido ether ligands are reported. The reaction of Li2[2,6-iPr2PhN(CH2CH2)]2O (Li2[DIPPNCOCN]) with 1 equiv. of UCl4 in THF generates [DIPPNCOCN]UCl3Li(THF)2(1), while reaction in toluene/ether gives salt-free [DIPPNCOCN]UCl2.1/2C7H8(2), which was identified by paramagnetically shifted 1H NMR. Reaction of 0.5 equiv. of {[tBuNON]UCl2}2([tBuNON]=[(CH3)3CN(Si(CH3)2)]2O2-) with 3.5 equiv. LiI in toluene and a minimal amount of THF results in [tBuNON]UI3Li(THF)2(3) and is very similar in structure to 1. {[MesNON]ThCl3Li(THF)}2(4), a dimeric complex with a Th2Li2Cl6 core, is prepared by reaction of Li2[2,4,6-Me3PhN(Si(CH3)2)]2O (Li2[MesNON]) with ThCl4 in THF. The analogous reaction in toluene did not yield the salt-free complex but rather a sterically crowded diligated compound, [MesNON]2Th (5), which was also structurally characterized. Complex 5 was prepared rationally by reacting 2 equiv. Li2[MesNON] with ThCl4 in toluene. The reaction of 1 and 3 with 2 equiv. of LiCH2Si(CH3)3 generates the stable, salt-free organoactinides [DIPPNCOCN]U(CH2Si(CH3)3)2(6) and [tBuNON]U(CH2Si(CH3)3)2(7). Complex 6 was structurally characterized. These reactions illustrate the viability of ate complexes as useful synthetic precursors.

The effect of subtle changes in the sigma-electron donor ability of 4-substituted pyridine ligands on the lead(II) coordination environment of (2,6-Me(2)C(6)H(3)S)(2)Pb (1) adducts has been examined. The reaction of 1 with a series of 4-substituted pyridines in toluene or dichloromethane results in the formation of 1:1 complexes [(2,6-Me(2)C(6)H(3)S)(2)Pb(pyCOH)](2) (3), [(2,6-Me(2)C(6)H(3)S)(2)Pb(pyOMe)](2) (4), and (2,6-Me(2)C(6)H(3)S)(2)Pb(pyNMe(2)) (5) (pyCOH = 4-pyridinecarboxaldehyde; pyOMe = 4-methoxypyridine; pyNMe2 = 4-dimethylaminopyridine), all of which have been structurally characterized by X-ray crystallography. The structures of 3 and 4 are dimeric and have psi-trigonal bipyramidal S(3)N bonding environments, with the 4-substituted pyridine nitrogen and bridging sulfur atoms in axial positions and two thiolate sulfur atoms in equatorial sites. Conversely, compound 5 is monomeric and exhibits a psi-trigonal pyramidal S(2)N bonding environment at lead(II). The observed structures may be rationalized in terms of a simple valence bond model and the sigma-electron donor ability of the 4-pyridine ligands as derived from the analysis of proton affinity values. Solid-state (207)Pb NMR experiments are applied in combination with density functional theory (DFT) calculations to provide further insight into the nature of bonding in 4, 5, and (2,6-Me(2)C(6)H(3)S)(2)Pb(py)(2) (2). The lead chemical shielding (CS) tensor parameters of 2, 4, and 5 reveal some of the largest chemical shielding anisotropies (CSA) observed in lead coordination complexes to date. DFT calculations using the Amsterdam Density Functional (ADF) program, which take into account relativistic effects using the zeroth-order regular approximation (ZORA), yield lead CS tensor components and orientations. Paramagnetic contributions to the lead CS tensor from individual pairs of occupied and virtual molecular orbitals (MOs) are examined to gain insight into the origin of the large CSA. The CS tensor is primarily influenced by mixing of the occupied MOs localized on the sulfur and lead atoms with virtual MOs largely comprised of lead 6p orbitals.

We report the structure and optical properties of a new Cu–cysteamine complex with a formula of Cu3Cl(SR)2 (R = CH2CH2NH2), which shows intense luminescence upon UV or X-ray excitation.

1,1'-bis(tert-butoxycarbonylamino)ferrocene (6), a protected derivative of 1,1'-diaminoferrocene, has been synthesized by a very convenient method and serves as a synthon for 1,1'-diaminoferrocene. Its structure in solid state and in solution has been studied by NMR and X-ray crystallography. 1,1'-bis(tert-butoxycarbonylamino)ferrocene serves as starting material for the synthesis of amino acid conjugates of L- and D-alanine. The structures of these bioconjugates have been studied by NMR and CD spectroscopy and X-ray crystallography and reveal that the chiral organization of the podant amino acid chains is controlled by the chirality of the attached amino acid. The substituents engage in strong intramolecular H-bonding generating 14-membered H-bonded rings, a motif previously unrealized in ferrocene-amino acid and peptide conjugates.

Stable dark red (M = Al) or dark green (M = Ga) neutral radicals {[PhB(mu-NtBu)2]2M} are obtained by the oxidation of their corresponding anions with iodine, and EPR spectra supported by DFT calculations show that the spin density is equally delocalized over all four nitrogen atoms in these spiroconjugated systems.