Yonghua Lin

Synthesis and structure of η6-benzenelanthanoidtris(aluminum tetrachlorides) (Ln = La, Nd, Sm)

The η6-benzene complexes of lanthanoids Ln(η6-C6H6)(AlCl4)3 · C6H6 (Ln = La (1), Nd (2), Sm (3)) have been prepared by the reaction of LnCl3 with activated AlCl3 in benzene. The crystal structures of 2 and 3 have been determined. Complexes 2 and 3 each crystallize from benzene in the triclinic space group P1; with a 9.40(2), b 9.74(3), c 16.61(5) A, α 96.69(2), β 93.54(3), γ 111.61(2)° for 2, and a 9.46(2), b 9.77(3), c 16.78(4) A, α 96.00(2), β 93.7692), γ 111.66(2)° for 3. The X-ray diffraction study has revealed that the central atom in Ln(η6-C6H6)(AlCl4)3-type complexes exerts no distinct influence on the molecular structure. Comparable M-ligand bond lengths reflect the difference in the ionic radii of neodymium and samarium.

Syntheses of bis(t-butylcyclopentadienyl)anthanoid chloride complexes and crystal structures of bis(t-butylcyclopentadienyl)chloro(bistetrahydrofuran)-praseodymium and bis(t-butylcyclopentadienyl)-chlorotetrahydrofuranyltterbium

Reaction of lanthanoid trichloride with two equivalents of sodium t-butylcyclopentadienide in tetrahydrofuran affords bis(t-butylcyclopentadienyl)lanthanoid chloride complexes (t-BuCp)2LnCl. nTHF (Ln = Pr, Nd, n = 2; Ln = Gd, Yb, n = 1). The compound (t-BuCp)2PrCl.2THF (1) crystallizes from THF in monoclinic space group P2(1)/c with unit cell dimensions a = 15.080(3), b = 8.855(2), c = 21.196(5) angstrom, beta = 110.34(2)degrees, V = 2653.9 angstrom-3 and D(calcd) = 1.41 g/cm3 for Z = 4. The central metal Pr is coordinated to two t-BuCp ring centroids, one chlorine atom and two THF forming a distorted trigonal bipyramid. The crystal of (t-BuCp)2YbCl.THF (2) belongs to the monoclinic crystal system, space group P2(1)/n with a = 7.726(1), b = 12.554(2), c = 23.200(6) angstrom, beta = 97.77(2)degrees, V = 2229.56 angstrom-3, D(calcd) = 1.50 g/cm3 and Z = 4. The t-BuCp ring centroids, the chlorine atom and the oxygen atom of the THF describe a distorted tetrahedron around the central ion of ytterbium.

Synthesis of bis(t-butylcyclopentadienyl)ytterbium(II). Derivatives and molecular structure of bis(t-butylcyclopentadienyl)bis(tetrahydrofuran)ytterbium(II)

Bis(η5-t-butylcyclopentadienyl)ytterbium(II) (t-C4H9C5H4)2Yb(THF)2 has been synthesized by metallic sodium reduction of the corresponding chloride (t-C4H9C5H4)2YbCl(THF) in THF. The reaction of (t-C4H9C5H4)2Yb(THF)2 with OPPh3 in toluene gives (t-C4H9C5H4)2Yb(OPPh3)(THF). (t-C4H9C5H4)2Yb(THF)2 crystallizes from THF in the monoclinic space group P21/n, with unit cell constants a 13.434(2), b 9.885(2), c 20.100(4) A, β 105.34(1)°, V 2573.99 A3 and Dcalcd 1.44 g cm−3 for Z = 4. Least-squares refinement of 4186 unique observed reflections led to a final R of 0.060. The two ring centroids of the t-butylcyclopentadienyl rings and the two oxygen atoms of the THF form a distorted tetrahedron around the central ion of ytterbium(II). The molecule has an approximate C2 cymmetry with the average bond distances: YbC(ring) 2.722(16) A, YbO(THF) 2.431(8) A, and YbCp (centroid) distance 2.442(0) A.

Synthesis of (t-C4H9C5H4)2Sm(DME) and its reactivity with phenylacetylene: Synthesis and structure of ((t-C4H9C5H4)2SmCCPh)2

Abstract The reaction of (t-C 4 H 9 C 5 H 4 ) 2 SmCl(DME) with Na in THF at 65°C gives (t-C 4 H 9 C 5 H 4 ) 2 Sm(DME). The complex (t-C 4 H 9 C 5 H 4 ) 2 Sm(DME) reacts with PhCCH in toluene to form ((t-C 4 H 9 C 5 H 4 ) 2 SmCCPh) 2 . ((t-C 4 H 9 C 5 H 4 ) 2 SmCCPh) 2 crystallizes from toluene in the monoclinic space group C 2/ n with unit-cell dimensions a 13.064(2), b 17.279(2), c 20.019(5) A, β 99.62(2)°, V 4455.4 A 3 and D calcd 1.47 gcm −3 for Z = 4. Least-squares refinement of 2201 unique observed reflections converged to a final R of 0.0498. The two (t-C 4 H 9 C 5 H 4 ) 2 Sm units are connected by asymmetrical alkynide bridges with independent SmC (alkynide) bond lengths of 2.56(1) and 2.62(1) A, SmCC angles of 158.8(1) and 100.6(9)°. The average SmC(ring) bond length is 2.722(13) A.

Synthesis and crystal structure of a four-coordinate aryloxo samarium complex [Sm(OAr)3(THF)](THF) (OAr = 2.6-ditertbutyl-4-methylphenoxo)

Abstract The aryloxo samarium complex [Sm(ArO)3(THF)](THF) has been prepared by the reaction of SmCl3 with 3 equiv. of NaOAr in THF. An X-ray crystallographic analysis shows the complex to be a four-coordinate aryloxide complex. Three oxygen atoms of aryloxo and one oxygen atom of THF coordinate to the samarium to form a distorted tetrahedron. The average SmO(Ar) distance is 2.151(7) A.

Preparation and molecular structure of methylbis(t-butyl-cyclopentadienyl)neodymium and -gadolinium

Abstract Bis(t-butylcyclopentadienyl)lanthanide chloride (Ln = Nd or Gd) reacts with one equivalent of methyllithium in ether/tetrahydrofuran to give the complex [(C 5 H 4 t Bu) 2 LnCH 3 ] 2 (Ln = Nd or Gd). The structure of [(C 5 H 4 t Bu) 2 NdCH 3 ] 2 has been determined by X-ray analysis. The crystals are monoclinic of space group Cm with a = 9.538(2), b = 23.298(4), c = 9.505(3) A, β = 119.53(2)°, V = 1828.0(7) A 3 , D calc. = 1.458 g/cm 3 and Z = 2 for the dimer. The two (C 5 H 4 t Bu) 2 Nd units in the dimer are connected by asymmetrical methyl bridges with independent NdC bond lengths of 2.70(2) and 2.53(2) A and NdCNd angles of 94.7(9) and 87.3(6)°.

Synthesis and crystal structure of bis(cyclopentadienyl)amido complex of neodymium, [Li(DME)3][(η5-C5H5)2Nd(NPh2)2]

Abstract [Li(DME)3] [(η5-C5H5)2Nd(NPh2)2] (1) was synthesized by the reaction of NdCl3 · 2LiCl · nTHF, 2 equivalents of CpNa (Cp = C5H5) and 2 equivalents of LiNPh2 and recrystallized from DME. Complex 1 was characterized by elemental analysis, IR and NMR spectroscopy and X-ray structural analysis. The crystal structure of 1 shows it to consists of [Li(DME)3]+ and [(η5-C5H5)2Nd(NPh2)2]− ion pairs. The neodymium atom was coordinated by two η5-bonded cyclopentadienyls and two σ-bonded diphenylamido ligands in a distorted tetrahedral arrangement, with the average distances NdCp(1) = 2.783(8), NdCp(2) = 2.767(9) (Cp indicates the ring carbons) and NdN = 2.428(7)A.

The reactivity of lanthanide alkyl compounds with phenylacetylene: synthesis and structure of [(ButCp)2LnCCPh]2 (LnNd, Gd)

[(Bu(t)Cp)(2)LnCH(3)](2) (Ln = Nd, Gd) react with PhC=CH to form the dimeric alkynide-bridged complexes [(Bu(t)Cp)(2)LnC=CPh](2) [Ln = Nd (I), Gd (II)]. Both compounds crystallized from toluene in the monoclinic space group C2/c. The two complexes are homologous, composed of asymmetric metal-alkynide bridges with Nd-C, Gd-C (alkynide) bond lengths of 2.602(4), 2.641(5) (I) and 2.532(6), 2.601(7) Angstrom (II), respectively. The average Nd-C (ring) and Gd-C (ring) distances are 2.746(13) and 2.703(19)Angstrom.

Synthesis and X-ray crystal structure of a monopentamethylcyclopentadienyl derivative of gadolinium {Na(μ2-THF)[(C5Me5)Gd(THF)]2(μ2-Cl)3(μ3-Cl)2}2·6THF

The reaction of GdCl3 with 1 equiv of NaC5Me5 generates a neutral complex C5Me5GdCl2(THF)3 and a novel complex {Na(mu-2-THF)[(C5Me5)Gd(THF)]2(mu-2-Cl)3(mu-3-Cl)2}2.6THF whixh recrystallizes from THF in triclinic, the space group P1BAR with unit cell dimentions of a 12.183(4), b 13.638(6), c 17.883(7) angstrom, alpha-110.38(3), beta-94.04(3), gamma-99.44(3)-degrees, V 2721.20 angstrom-3 and D(calc) 1.43 g cm-3 for Z = 1. Least-squares refinement of 2170 observed reflections led to a final R value of 0.047. The title complex consists of two Na(mu-2-THF)[(C5Me5)Gd(THF)]2(mu-3-Cl)3(mu-3-Cl)2 units bridged together via two mu-2-THF to Na coordination. Each Gd ion is surrounded by one C5Me5 ligand, two mu-3-Cl, two mu-2-Cl and one THF in a distorted octahedral arrangement with average Gd-C(ring) 2.686(33), Gd-mu-2-Cl 2.724(7), Gd-mu-3-Cl 2.832(8) and Gd-O 2.407(11) angstrom. The sodium ion coordinates to two bridging THF, two mu-2-Cl and two mu-3-Cl to form a distorted octahedron with average Na-mu-2-O, Na-mu-2-Cl and Na-mu-3-Cl of 2.411(21), 2.807(15) and 2.845(12) angstrom, respectively.

SYNTHESES OF INDENYL LANTHANIDE DERIVATIVES AND THE MOLECULAR STRUCTURES OF (C9H7)2PRCL(THF)2 AND (C9H7)3LA(THF)

The reaction of anhydrous PrCl3 with Na(C9H7) in 1.2 mole ratio in THF gives [(C9H7)(2)PrCl(THF)](2)1. 1 crystallized in monoclinic system, space group P2(1)/c with a = 7.808(2), b = 17.796(6), c = 14.070(4) Angstrom, beta = 93.97(2)degrees, V= 1950.3(9) Angstrom(3), Dcalcd = 1.63 g/cm(3) and Z = 2. Each Pr ion is surrounded by two indenyl, two Cl and one THF in a roughly trigonal bipyramid arrangement with average Pr-C(ring) and Pr-Cl distances of 2.81 and 2.84 Angstrom. The reaction of LaCl3 with Na(C9H7) in 1:3 mole ratio gives (C9H7)(3)LaTHF 2, which crystallizes in the monoclinic space group P2(1)/a with unit cell constants a = 21.871(8), b = 10.585(3), c = 23.652(7) Angstrom,beta = 114.62(2)degrees, V = 4977.9 Angstrom(3) and Z = 8