Jason A. Kautz

SYNTHESIS, CHARACTERIZATION AND STRUCTURAL ANALYSES OF THREE LANTHANIDE CYANIDE-BRIDGED COMPLEXES

Abstract Three lanthanide (Ln) complexes (DMF)4(H2O)3LnFe(CN)6 · H2O, where Ln = Er, Yb, and Lu, were structurally determined by means of three-dimensional single-crystal X-ray diffraction analysis. These systems crystallize in the centrosymmetric monoclinic space group P21/c (No. 14) with Z = 4 and respective lattice constants of a = 13.956(2), 13.952(1), 13.937(3); b = 8.867(4), 8.864(1), 8.862(2); c = 24.857(3), 24.812(2), 24.770(5) Å; and β = 96.30(1)°, 96.33(1)°, 96.30(3)°. Final least-squares full-matrix refinements based on 3499, 3367, and 2555 unique reflections yielded reliability (R) index factors of 0.071, 0.051, and 0.032, respectively. In each complex, the coordination about the central Ln ion is eight in a square-antiprism arrangement and the coordination about the Fe ions is six, oriented octahedrally. Cyanide bridging links the Ln ions to the FeC6 groups. Molecules in the crystal lattice of each complex are held together by van der Waals forces and a network of hydrogen bonding. Characterization includes physical property determinations, conoscopical studies, thermal gravimetric analyses, and IR spectrometric identifications. Selected bond lengths and angles are tabularized and a synthesis of these compounds is presented.

Nitrosyl-cobalt monocarbollide complexes

Abstract The carborane anion [closo-2-CB10H11]− undergoes a polyhedral expansion reaction with [Co(CO)3(NO)] in tetrahydrofuran (THF) to afford [2-CO-2-NO-closo-2,1-CoCB10H11]−, isolated as the [N(PPh3)2]+ salt 1a. An X-ray diffraction study confirmed that the NO group is linearly bonded to cobalt. The CO ligand in 1a is readily replaced by PPh3 in the presence of Me3NO, or by PEt3 or CNBut directly, to give the species [N(PPh3)2][2-L-2-NO-closo-2,1-CoCB10H11] [L=PPh3 (1b), PEt3 (1c), CNBut (1d)]. Reactions of these anionic complexes with electrophilic reagents are exemplified by treatment of 1c with CF3SO3Me in CH2Cl2–THF to give the neutral, zwitterionic B-THF species [2-NO-2-PEt3-7-O(CH2)4-closo-2,1-CoCB10H10] (3a), and by the reaction of 1b with [CuCl(PPh3)]4 and Tl[PF6] in THF to give bimetallic [2,7,11-{Cu(PPh3)}-7,11-(μ-H)2-2-NO-2-PPh3-closo-2,1-CoCB10H9] (4b). X-ray diffraction analysis of crystals of 4b confirmed the presence of a CoCu bond.

2-(3-tert-Butyldimethylsiloxy-4-methoxyphenyl)-6-methoxy-3-(3,4,5-trimethoxybenzoyl)indole

In the crystal structure of the title compound, C(32)H(39)NO(7)Si, all geometric parameters fall within experimental error of expected values. The analysis of molecular-packing plots reveals an infinite two-dimensional linear array running parallel to the b axis, formed by one N[bond]H...O intermolecular hydrogen-bonding interaction. Several potential C[bond]H...O interactions are also present.

Synthesis and characterization of complexes of Te(IV) with sulfur and selenium containing ligands: Crystal and molecular structure of trichloro(4-methoxyphenyl)-tellurium(IV).N-methylbenzothiazole-2-(3H)-thione

We report the synthesis and characterization of two new complexes of trichloro(4-methoxyphenyl)tellurium(IV) with N -methylbenzothiazole-2-( 3H )-thione ( 1 ) and N -methylbenzothiazole-2-( 3H )-selone ( 2 ). Both are obtained as air-stable complexes by the addition of a 1:1 molar ratio of the substituted tellurium(IV) trichloride with the appropriate ligand in tetrahydrofuran under an atmosphere of dry nitrogen. Both ( 1 ) and ( 2 ) have been characterized by 1 H and 13 C NMR spectroscopy, elemental analysis, and, in the case of ( 1 ), by a single crystal x-ray diffraction study. The molecular structure of ( 1 ) shows an approximately square-based pyramidal structure with one short Te--Cl bond [2.388(2)Å] trans to a very long Te--S linkage [2.883(2)Å]. A comparison with the related structures of some heavy main group elements is included.

A dinuclear cyanide-bridged complex, [(DMF)4(H2O)3LuCo(CN)6]·H2O

The crystal structure of the bimetallic cyanide bridged complex [(DMF)4(H2O)3LuCo(CN)6]·H2O (1) was obtained by single-crystal X-ray diffraction. The central lutetium(III) ion is eight coordinate arranged in a square antiprism while the cobalt(III) ion is six coordinate, oriented octahedrally. Molecules in the crystal lattice are held together by a network of hydrogen bonding. Crystallization of 1 occurs in the centrosymmetric monoclinic space group P21/c (No. 14) with a = 13.875(2), b = 8.8352(9), c = 24.633(2) Å β = 96.392(8)° and Z = 4.

Syntheses, characterization, and structural analyses of several f-block isothiocyanatonitrato complexes

Reactions of tetra-n-butylammonium thiocyanate with lanthanide and uranyl nitrates yield complexes of the general type [(Bu)4N]x[M(NCS)y(NO3)z]. Samples of [(Bu)4N]2 [UO2(NCS)3( NO3)] (1), [(Bu)4N]3[Yb(NCS)4(NO3)2] (2), and [(Bu)4N]3[Nd(NCS)4(NO3)2rsqb; (3) were prepared from alcohol solutions. Crystallization of 1 occurs in the centrosymmetric monoclinic space group C2/c (No. 15) with a = 17.949(4) Å, b = 16.587(3) Å, c = 16.763(3) Å; β = 99.77(3)°; and Z = 4. The seven-coordinate uranium(VI) ion exhibits a pentagonal bipyramid coordination environment. Crystallization of 2 occurs in the centrosymmetric orthorhombic space group Pnnn (No. 48) with a = 12.530(2) Å, b = 12.9440(10) Å, c = 21.203(2) Å; Z = 2. The eight-coordinate ytterbium(III) ion expresses a dodecahedral coordination environment. Crystallization of 3 occurs in the noncentrosymmetric monoclinic space group Cc (No. 9) with a = 16.556(2) Å, b = 18.130(2) Å, c = 23.984(4) Å; Z = 4. The 10-coordinate neodymium(III) ion exhibits a dodecahedral coordination environment. Characterization includes physical property determinations, conoscopic studies, IR spectroscopic identifications, and UV spectral data. Details of the syntheses along with selected bond distances and angles are presented and discussed.

New synthesis of [RuH(CO)(PPh3)2L2][BF4] [L2 = 2py, 2(4-Mepy) or bpy] and X-ray crystal structure of [RuH(CO)(PPh3)2(4-Mepy)2][BF4]

Abstract The title compounds were prepared by reaction of RuH2(CO)(PPh3)3 with [C7H7][BF4] in the presence of excess pyridine, 4-picoline or 2,2′-bipyridine. The compounds were characterized by IR, 1 H and 31 P NMR, and X-ray crystallography (for the 4-Mepy complex). The spectroscopic data as well as the results of the X-ray crystal structure show that the complexes contain trans-oriented phosphines and cis-pyridines. Details of the structural content and selected bond distances and angles are internally consistent.

Synthesis, characterization, and structural analysis of (1:2) mixed cationic lanthanide potassium hexacyanoferrate (II) tetrahydrate

Abstract The crystal structural investigation of 1:2 ( La Pr ) KFe ( CN ) 6 ·4 H 2 O (I) has been determined from three-dimensional, single-crystal, X-ray diffraction data and refined by least-squares method to yield a final reliability (R) factor of 0.016 based on 363 unique reflections. The title compound crystallizes in the hexagonal space group P6 3 m (No. 176) with a = 7.381 (1), c = 13.855(3) A . For Z = 2, the calculated density is 2.354 Mg m−3 (exp., 2.347(4) Mg m−3). The coordination about the lanthanide central atoms is nine, and the geometric polyhedron is a tricapped trigonal prism (TTP). Cyanide bridging links the octahedral FeC6 groups to the 9-coordinated ( La Pr ) N 6 ( H 2 O ) 3 groups. The uncoordinated water molecule and the potassium ion occupy holes in the lattice along the threefold axis above and below the lanthanide atoms. Selected bond distances and angles are presented as well as discussions of the synthesis, TGA, IR, and digital SEM/EDS results, and other peripheral studies of I.

Structural analysis of tris(tetra-n-butylammonium) hexakisisothiocyanatolutetinate(III)

Abstract The structural analysis of [(n-C4H9)4N]3[Lu(NCS)6] (I) using single-crystal diffraction data and full-matrix least-squares refinement has yielded reliability factors of R=0.060 and Rw=0.071 based on 5578 observed reflections. The hexaisothiocyanate complex crystallizes in the centrosymmetric triclinic space group P 1 with unit cell dimensions a=12.405(2), b=12.830 (2), c=22.699(2) A, α=90.87(1), β=92.10(1), γ=96.67(1)°, V=3585.1(8) A3 and Z=2. The observed density is 1.16(1) g cm−3 (Dcalc=1.159 g cm−3). The molecular unit consists of three separate cationic tetra-n-butylammonium groups and an independent hexakisisothiocyanatolutetium anionic group in which the six thiocyanate ligands octahedrally coordinate through the N atom to the Lu central atom. Selected bond distances and angles are presented as well as references to the synthesis of I and peripheral studies.

Synthesis and reactivity of the rhodium monocarbollide complexes [1-NHCMe2-2-Cl-2-PPh3-closo-2,1-RhCB10H10] and [1-NH3-2-Cl-2-PPh3-closo-2,1-RhCB10H10]

Abstract The carborane 7-NHCMe2-nido-7-CB10H12 reacts with [RhCl(PPh3)3] in toluene at reflux temperatures to give the charge-compensated 16-electron Rh(III) complex [1-NHCMe2-2-Cl-2-PPh3-closo-2,1-RhCB10H10] (1) in good yield. The structure of this product was established by X-ray diffraction (XRD). Upon methanolysis 1 affords [1-NH3-2-Cl-2-PPh3-closo-2,1-RhCB10H10] (2), also a 16-electron charge-compensated Rh(III) complex. Some reactions of 2 were investigated. At room temperature, in the presence of Na2CO3, it reacts with acetic, methacrylic, and crotonic anhydrides to give the complexes [1,2-μ-{NHC(R)O}-2-PPh3-closo-2,1-RhCB10H10] [R=Me (3), CMeCH2 (4a), and (E)-CHCHMe (4b)], respectively. Benzoyl bromide with 2 and Na2CO3 yields [1,2-μ-{NHC(Ph)O}-2-PPh3-closo-2,1-RhCB10H10] (5). An XRD study of 4a established that the acyl group is coordinated to the rhodium through the oxygen. In the crystal molecules lie pair-wise linked by a BH⇀Rh bridge so that in one molecule the rhodium atom has a 16-electron valence shell and in the other an 18-electron configuration. However, in solution NMR studies reveal that only monomeric molecules occur. With CNBut in the presence of Na2CO3, compound 2 affords [1-NH2-2,2-(CNBut)2-2-PPh3-closo-2,1-RhCB10H10] (7), the structure of which was determined by XRD. The NMR parameters of the new compounds are reported and discussed.