Five homologues of the new complex series [LnL(mu-OTf)](2) with Ln = Pr (1), Nd (2), Sm (3), Y (4), Yb (5) have been prepared from [Ln(OTf)(3)] and Na2L, where L designates two cyclopentadienyl rings tethered by a 2,6-bis(methylene)pyridyl unit and -OTf the triflate (trifluoromethanesulfonate) anion. According to crystal structure analyses of 2, 4, and 5, each triflate ligand bridges two Ln ions (Ln-O-S(O)-O'-Ln'), while, owing to substantial Ln-N(pyridyl) bonding, the LnL fragments turn out to be notably rigid entities. Nevertheless, the variable-temperature (VT) H-1 NMR spectra of all complexes reveal notable fluxionality. According to a detailed VT F-19 NMR study of 4, two dinuclear isomers, differing in the trans and cis orientations, respectively, of their two L fragments, interconvert with a negligibly small entropy of activation DeltaS(double dagger). A motion reminiscent of the Berry turnstile would most plausibly explain the experimental findings.

Five homologues of the new complex series [LnL(μ-OTf)] 2 with Ln = Pr (1), Nd (2), Sm (3), Y (4), Yb (5) have been prepared from [Ln(OTf) 3 ] and Na 2 L, where L designates two cyclopentadienyl rings tethered by a 2,6-bis(methylene)pyridyl unit and -OTf the triflate (trifluoromethanesulfonate) anion. According to crystal structure analyses of 2, 4, and 5, each triflate ligand bridges two Ln ions (Ln-O-S(O)-O'-Ln'), while, owing to substantial Ln-N(pyridyl) bonding, the LnL fragments turn out to be notably rigid entities. Nevertheless, the variable-temperature (VT) 1 H NMR spectra of all complexes reveal notable fluxionality. According to a detailed VT 1 9 F NMR study of 4, two dinuclear isomers, differing in the trans and cis orientations, respectively, of their two L fragments, interconvert with a negligibly small entropy of activation ΔS . A motion reminiscent of the Berry turnstile would most plausibly explain the experimental findings.

Five homologues of the new complex series [LnL(μ-OTf)] 2 with Ln = Pr (1), Nd (2), Sm (3), Y (4), Yb (5) have been prepared from [Ln(OTf) 3 ] and Na 2 L, where L designates two cyclopentadienyl rings tethered by a 2,6-bis(methylene)pyridyl unit and -OTf the triflate (trifluoromethanesulfonate) anion. According to crystal structure analyses of 2, 4, and 5, each triflate ligand bridges two Ln ions (Ln-O-S(O)-O'-Ln'), while, owing to substantial Ln-N(pyridyl) bonding, the LnL fragments turn out to be notably rigid entities. Nevertheless, the variable-temperature (VT) 1 H NMR spectra of all complexes reveal notable fluxionality. According to a detailed VT 1 9 F NMR study of 4, two dinuclear isomers, differing in the trans and cis orientations, respectively, of their two L fragments, interconvert with a negligibly small entropy of activation ΔS . A motion reminiscent of the Berry turnstile would most plausibly explain the experimental findings.

The admixture of aqueous Me2SnCl2–Me3SnCl solutions to solutions of K3[Co(CN)6] in the molar ratios 3:0:2 and 1:1:1, respectively, affords precipitates of [(Me2Sn)3{Co(CN)6}2·6H2O] (1) and [(Me2Sn)(Me3Sn)Co(CN)6] (2). Another synthesis of 2 is based upon the bromination of [(Me3Sn)3Co(CN)6] in MeOH. The crystal structure analysis of 1 reveals stacks of infinite planar ribbons built up of trans-Me2Sn(μ-NC)4 and trans-Me2Sn(μ-NC)2(OH2)2 units as well as of trans-Co(CN)2 fragments with terminal CN-ligands. Sn←OH2⋯(NC)2 hydrogen bonds interlink adjacent ribbons. Multinuclear (13C, 15N, 59Co, 119Sn) CPMAS solid-state NMR studies of 1 suggest some intra-ribbon dynamics, and help in proposing both a plausible architecture for anhydrous 2 and a better understanding of the nature of another precipitate 5 resulting from the admixture of a Me2SnCl2/Me3SnCl solution to a solution of K4[Fe(CN)6] (1:2:1).

The crystal structure of the title compound, [ZrCl4(C4H8O)(2)](2)O or [Zr2Cl6O(C4H8O)(4)], (I), was solved at room temperature and compared with that of the earlier reported complex [ZrCl3(MeOCH2CH2OMe)(2)](2)O, (II). In both molecules, two equivalent quasi-octahedral fragments involving one axial (ax) and one equatorial (eg) ether oxygen share one bridging oxide functionality However, the point symmetry of (I) is only C-2. while that of (II) is C-2h The dihedral angle of the O-eq-Zr-Zr-i-O-eq(i) fragment of (I) [symmetry code: (i) 1-x, y, 1/2-z] is 115.3(1)degrees [180.0 degrees in (II)] and the Zr-O-Zr-i angle is 174.8(2)degrees [180.0 degrees in (II)].

Notably distorted, adamandoid Cu10 cages with Cu···Cu edges of 10.795(6) A (Cu−CN−Sn(Me3)−NC−Cu) and 7.142(5) A (Cu−pyrazine−Cu) are the basic building blocks of the novel supramolecular assembly [CuCN·Me3SnCN·C4H4N2] (C4H4N2 = pyrazine). Interpenetration of three equivalent, distorted-diamondoid frameworks affords comparatively compact crystal packing.

Nine novel organolanthanoid (Ln=Pr and Yb) complexes of the general type [LnCp(2)'(mu-OCHR(1)Z)](2) (Cp'=C5H5 or CH3C5H4, R-(1) = H or Me) containing exclusively chiral, oxygen-functionalized alkoxide ligands with Z((1)) = CHR(2)OMe (R-(2) = Me or Ph), Z((2)) = COOiBu and Z((3))= CH2COOEt have been prepared and further characterized. While five (of six) Pr complexes give rise to solution 1(H)-NMR spectra indicative of stable (on the NMR time scale) intramolecular coordination of Z via an additional O --> Pr bond (as in form B of Fig. 1), the corresponding Yb-homologues turn out to be fluxional at room temperature. In contrast, X-ray diffraction studies of two new representatives with Ln = Yb, and of one selected complex with Ln = Pr, confirm the earlier suggested view (Steudel et al., J. Organomet. Chem. 556 (1998) 229) that in the solid state the central Ln(III) ion adopts the highest possible coordination number. (C) 1998 Elsevier Science S.A. All rights reserved.

Reaction of K-3[Cu(CN)(4)] with Me3SnCl and 4,4'-bipyridine (bpy) affords the novel ternary adduct [CuCN . Me3SnCN . 0.5bpy], 2, as yellow, cubelike crystals. The supramolecular architecture of 2 consists, according to a single-crystal X-ray study, of remarkably porous, approximately planar sheets held together by almost perpendicular bpy pillars. Basic building blocks of the sheets are {Cu-2(mu-ChT)(2)(CN)(2)} fragments whose N atoms are connected, via Me3Sn bridges, with the N atoms of adjacent fragments. 2 crystallizes in space group P2(1)/c with (at 20 degrees C) a 10.035(4) Angstrom, b = 11.980(3) Angstrom, c = 12.425(5) Angstrom beta = 110.94(3)degrees, and Z = 4. The dinuclear building blocks resemble strongly those of the long known, but chemically more labile, layered coordination polymer [CuCN . NH3], 1. Although the lattice of 2 consists of two equivalent, ideally interpenetrating 3D frameworks, spacious, straight channels of a cross section of ca. 10 Angstrom x 5 Angstrom persist in this unprecedented structure. The likewise polymeric new adduct [CuCN . Me3SnCN . H2O] (3) obtained from K-3[Cu(CN)(4)] and Me3SnCl in the absence of bpy may be considered as a formal precursor of 2.

Reaction of K(3)[Cu(CN)(4)] with Me(3)SnCl and 4,4'-bipyridine (bpy) affords the novel ternary adduct [CuCN.Me(3)SnCN.0.5bpy], 2, as yellow, cubelike crystals. The supramolecular architecture of 2 consists, according to a single-crystal X-ray study, of remarkably porous, approximately planar sheets held together by almost perpendicular bpy pillars. Basic building blocks of the sheets are {Cu(2)(&mgr;-CN)(2)(CN)(2)} fragments whose N atoms are connected, via Me(3)Sn bridges, with the N atoms of adjacent fragments. 2 crystallizes in space group P2(1)/c with (at 20 degrees C) a = 10.035(4) Å, b = 11.980(3) Å, c = 12.425(5) Å, beta = 110.94(3) degrees, and Z = 4. The dinuclear building blocks resemble strongly those of the long known, but chemically more labile, layered coordination polymer [CuCN.NH(3)], 1. Although the lattice of 2 consists of two equivalent, ideally interpenetrating 3D frameworks, spacious, straight channels of a cross section of ca. 10 Å x 5 Å persist in this unprecedented structure. The likewise polymeric new adduct [CuCN.Me(3)SnCN.H(2)O] (3) obtained from K(3)[Cu(CN)(4)] and Me(3)SnCl in the absence of bpy may be considered as a formal precursor of 2.

Novel supramolecular assemblies 2 of the composition [(nBu(4)N)(Me3E)(2)M(CN)(6) . H2O] (E=Sn, Pb; M=Fe, Co) have been obtained both by spontaneous self-assembly of small ions and by exchange remodeling of the known, sparingly soluble, coordination polymers [(Me3E)(3)M(CN)(6)]. Product 2a (E=Sn, M=Fe) was characterized by single-crystal X-ray crystallography, and its diamagnetic homologue 2b (E=Sn, M=Co) by in-depth multinuclear (C-13, N-15, Co-59, Sn-119) solid-state magnetic resonance spectroscopy. The architecture of 2a is based on slightly puckered, porous nets involving coordinative N-cyanide-->Sn and O-water-->Sn bonds. These nets are stacked regularly and are held together by O-H ... N and (nBu)alpha-C-H ... N hydrogen bonds. This produces nanometer-sized channels that host two thirds of the nBu(4)N(+) ions. Unexpected [(Me3Sn(OH2)(2)](+) ions and the remaining third of the nBu(4)N(+) ions are trapped between adjacent [-Fe-CN-Sn-NC-](infinity) chains. Both the methods of formation of 2a/b and their (probably analogous) structures are suggestive of a pronounced superiority of concerted O-->Sn and D-H ... N bonding (D=OH and CH2) over an exclusive N-->Sn coordination.

The crystal structure of [(nBu4N){(Me3Sn)2OH}{Ni(CN)4}][Ni(CN)2 · 2Me3SnCN · (nBu4N)OH] (1), the formal 1:1-addition product of polymeric [(Me3Sn)2Ni(CN)4][Ni(CN)2 · 2Me3SnCN] and (nBu4N)OH, has been revisited at 153 K. Owing to the presence of distinct (Me3Sn)2OH · · ·NC hydrogen bonds, infinite, negatively charged layers containing cyclic [{(Me3Sn)2OH}2{μ(NC)2Ni(CN)2}2]2− units alternate with layers of nBu4N+ ions. CPMAS solid-state NMR spectra (13C, 15N, 119Sn) strongly support nonsymmetric building blocks with exceedingly weak SnN bonds.

The first crystallographically elucidated example of a chiral organolanthanoid alkoxide complex [LnCp′2(μ-OCHRCHR1NR2R3)]2 with Ln=Sm, R=Ph, R1=H, R2=Me and R3=CH2Ph (11; prepared from the pure (1R)-(+)-aminoalcohol) is presented. While crystalline 11 involves distinct N–Sm bonds (283.3 pm) in enantiomorphic {(-CHPhCH2)(CH2Ph)MeN–Sm} fragments, its solution NMR spectra (1H, 13C) suggest a complete or partial rupture of the N–Sm bonds. More systematic solution 1H-NMR studies of likewise chiral representatives of the series with R=H, R1=Et, R2, R3=Me and Ln=Pr, Nd, Sm, Yb and Lu, respectively, indicate that at room temperature (r.t.) only the dissolved complexes with Ln=Pr, Nd and Sm involve N–Ln bonds that are stable on the NMR time scale. The homologues with Ln=Yb and Lu are fluxional. The paramagnetic nature of the complexes with Ln=Pr, Nd and Yb turns out to be particularly helpful for the structural deductions in magnifying significantly e.g. the diastereotopic splitting of the ring proton resonances of various CH3C5H4 ligands.

The novel yttrium(III) complex [YL(μ-OH)]2 (1) with L = {2,6-(C5H4CH2)2C5H3N}2− wherein C5H3N represents a 2,6-pyridine-diyl unit has been obtained by partial hydrolysis of the new homoleptic complex [(YL)2(μ-L)], some lanthanoid homologues of which have so far been characterized only spectroscopically. The crystal structure of 1 resembles that reported earlier for the corresponding (CH2)2O(CH2)2-tethered complex [YL′(M-OH)]2 (3) with L′ = {(C5H4CH2CH2)2O}2− and suggests significant N-Y bonding, although the N-Y distance is relatively long (2.621 (3) Å).

Reaction of K(3)[Cu(CN)(4)] with Me(3)SnCl and 4,4'-bipyridine (bpy) affords the novel ternary adduct [CuCN.Me(3)SnCN.0.5bpy], 2, as yellow, cubelike crystals. The supramolecular architecture of 2 consists, according to a single-crystal X-ray study, of remarkably porous, approximately planar sheets held together by almost perpendicular bpy pillars. Basic building blocks of the sheets are {Cu(2)(&mgr;-CN)(2)(CN)(2)} fragments whose N atoms are connected, via Me(3)Sn bridges, with the N atoms of adjacent fragments. 2 crystallizes in space group P2(1)/c with (at 20 degrees C) a = 10.035(4) Å, b = 11.980(3) Å, c = 12.425(5) Å, beta = 110.94(3) degrees, and Z = 4. The dinuclear building blocks resemble strongly those of the long known, but chemically more labile, layered coordination polymer [CuCN.NH(3)], 1. Although the lattice of 2 consists of two equivalent, ideally interpenetrating 3D frameworks, spacious, straight channels of a cross section of ca. 10 Å x 5 Å persist in this unprecedented structure. The likewise polymeric new adduct [CuCN.Me(3)SnCN.H(2)O] (3) obtained from K(3)[Cu(CN)(4)] and Me(3)SnCl in the absence of bpy may be considered as a formal precursor of 2.

Although the CHż;O hydrogen bond is practically ubiquitous in supramolecular assemblies, findings of corresponding CHż;N bridges have so far been comparatively rare. The crystal structures of four related, novel co-ordination polymers involving R3Sn+, [M(CN)n]m− and nBu4N+ ions as essential building blocks have been examined in view of the involvement of CHż;N bridges between any of the α-CH2 groups of the nBu4N+ ions and N atoms of the CN ligands. Distinct CHż;N bridges with (in part) unprecedentedly short Cż;N contacts (down to 317 pm) have in fact been found, primarily with cyanide N atoms not engaged in simultaneous N → Sn bonding. Another cation that turns out to be capable of forming significant C Hż;N bridges even with metal-bridging CN-ligands is the complex[CoIII(C5H5)2]+.

The new coordination polymer [(Me3SnIV)(3)Rh-III(SCN)(6)] = (3)(infinity)[Rh{mu-(SCNSnMe3NCS)}(3)] (5) is readily accessible by straightforward self-assembly of [Rh(SCN)(6)](3-) and (dehydrated) {Me3Sn}(aq)(+) ions. The architecture of 5 is strongly reminiscent of ''super-Prussian-blue'' systems reported earlier: there is a three-dimensional (3-D) framework involving {Rh-8} pseudocubes as the basic building blocks, the Rh3+ ions being held apart by novel, nonlinear {SCN-SnMe3NCS} spacers (d(Rh ... Rh) = 1.27 nm). The complete lattice consists of two equivalent and independent, ideally interwoven 3-D frameworks. Three homologues of 5 with slightly modified R3Sn units (R = Et, nPr and nBu) have been prepared as well, but display X-ray powder diffraction patterns notably different from that of 5.

The title complex 2 = [{O(Me2SiC9H6)2}ZrCl2](SiC9H6 = 2 silylated indenyl group) has been prepared in a way slightly different from that published recently by Rausch and coworkers (J. Organomet. Chem., 501 (1995) 375). In contrast to the earlier report, the 1H NMR spectra of 2 in C6D6 and CD2Cl2 reflect clearly the presence of both rac-2 and meso-2 (ca. 4:1). From toluene, 2 crystallizes as a racemic mixture; rac-2: monoclinic; space group P2√c, a = 1278.2(4), b = 1196.2(4), c = 1567.8(6) pm; β = 100.8(3)°; R1 = 0.0314 (wR2 = 0.0771). The high-resolution 1H NMR spectrum of rac-2 does not match with the crystal structure: most probably, rapid (on the NMR time scale) racemization takes place down to at least −80°C.