Coordination chemistry of anticrowns. Complexation of cyclic trimeric perfluoro-o-phenylenemercury (o-C6F4Hg)3 with the cyanoborohydride anion [H3BCN]− and triethylamineborane Et3NBH3

As was shown by IR spectroscopy, the reaction of the three-mercury anticrown (o-C₆F₄Hg)₃ (1) with the [H₃BCN]ion in THF affords the complexes {[(o-C₆F₄Hg)₃][H₃BCN](5) and [(o-C₆F₄Hg)₃]₂[H₃BCN](6). Complex 6 was isolated from solution in the analytically pure state. According to X-ray diffraction data, complex 6 has a double-decker sandwich structure, in which the borohydride group of the [H₃BCN]^? anion is bound to one anticrown molecule by three B-H-Hg bridges, whereas the cyanide group is cooperatively coordinated by three mercury centers of another molecule 1 through the nitrogen atom. The reaction of compound 1 with triethylamineborane Et₃NBH₃ in THF affords the 1: 1 complex ～[(o-C₆F₄Hg)₃][Et₃NBH₃]～ (7). In this adduct, the binding of the aminoborane to the mercury anticrown is also accomplished by B-H-Hg bridges. The stability constants of complexes 5 and 6 in THF were determined.     

Crystal structure of boron difluoride 1-naphthylbutanedionate-1,3(C10H7COCHCOCH3BF2). π-stacking interaction and luminescence

The crystal structure and luminescent properties of boron difluoride 1-naphthyl-butandionate-1,3 (1) (C₁₀H₇COCHCOCH₃BF₂) are determined and analyzed. The molecules of compound 1 are packed in the crystal into infinite stacks due to π-stacking interactions. A feature of the structure of 1 is a fragment of four neighboring molecules, the π-systems of which participate in π…π interactions of different types: naphthyl…naphthyl (head-to-head) and naphthyl…chelate (head-to-tail). The data of time resolved luminescent spectroscopy and quantum chemical computations show that in crystals and concentrated solutions of 1, one excimer structure occurs corresponding to the head-to-tail overlap.     

Synthesis and structural characterization of binuclear ytterbium(III) complexes with 2-amino and 3-amino benzoic acid

Two novel homobinuclear ytterbium(III) complexes, [Yb₂(2AMB)₆(H₂O)₄] · 2C₂H₆O (I) and Yb₂(3AMB)₆(H₂O)₄] · 3H₂O (II) (2AMB = 2-aminobenzoic acid, 3AMB = 3-aminobenzoic acid) have been synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis and X-ray crystallography (CIF files CCDC nos. 950103 (I), 921652 (II)). Complex I crystallizes in triclinic space group \(P\bar 1\) and complex II crystallizes in monoclinic space group P2₁/n. X-ray analysis shows that both complexes (I, II) have the dinuclear structure. The central Yb³⁺ ions in both complexes are eight-coordinated adopting distorted YbO₈ dodecahedral geometry. Each Yb³⁺ ion is coordinated to two O atoms from bridging carboxylate, four O atoms from the chelating carboxylate ligands and two O atoms of water molecules. The crystal structure of I and II are stabilized by N-H…O, O-H…O, O-H…N, and C-H…O hydrogen bonds, C-H…π interactions and weak π-π stacking interactions.     

Coordination chemistry of mercury-containing anticrowns. Synthesis and structures of the complexes of cyclic trimeric perfluoro-o-phenylenemercury with ethanol, THF and bis-2,2′-tetrahydrofuryl peroxide

Cyclic trimeric perfluoro-o-phenylenemercury (o-C₆F₄Hg)₃ (1) is capable of reacting with ethanol to form a 1:1 complex, {[(o-C₆F₄Hg)₃](EtOH)} (2), having a pyramidal structure. The ethanol molecule in 2 is coordinated through the oxygen atom to all Hg atoms of the macrocycle. The interaction of 1 with THF followed by drying of the product obtained in vacuum also gives the corresponding pyramidal 1:1 complex {[(o-C₆F₄Hg)₃](THF)} (3). However, when a THF solution of 1 is slowly concentrated to a small volume and the resulting crystals are not dried, three cocrystallized adducts, viz., {[(o-C₆F₄Hg)₃](THF)₂} (4), {[(o-C₆F₄Hg)₃](THF)₃} (5) and {[(o-C₆F₄Hg)₃](THF)₄} (6), containing two, three and even four THF molecules, respectively, are produced. Complex 4 has a bipyramidal structure. Complexes 5 and 6 are also characterized by the presence of a bipyramidal fragment formed by two coordinated THF species. The topological analysis of the DFT-calculated function of the electron density distribution in the crystals of 2 and 3 revealed the critical points (3, −1) on each of the three Hg···O lines, which is in accord with the X-ray diffraction data indicating on the presence of the triply coordinated Lewis base molecule in both adducts. If a THF solution of 1 is held for a month at 20 °C on air under stirring, a sandwich complex of 1 with previously unknown bis-2,2′-tetrahydrofuryl peroxide (THFPO) is formed. The THFPO ligand in this sandwich, {[(o-C₆F₄Hg)₃]₂(THFPO)} (7), provides all its four oxygen atoms for the bonding to the molecules of 1. Two of these oxygen atoms, belonging to the tetrahydrofuryl moieties, are cooperatively bound each by three Hg atoms of the neighbouring macrocyclic unit whereas two others, belonging to the peroxide group, coordinate to a single Hg atom of the adjacent macrocycle.     

Unexpectedly low affinity of aromatic disulfides for π-stacking interactions of the arene-polyfluoroarene type

1,2,3,4,5-Pentafluorodiphenyl disulfide (1) was synthesized from C₆F₅SCl and C₆H₅SSiMe₃ in quantitative yield. The homo-crystals of disulfide 1 and co-crystals of 1,1′,2,2′,3,3′,4,4′,5,5′-decafluorodiphenyl disulfide (2) with naphthalene (stoichiometry 1:2, complex 4) and diphenyl disulfide (3) with octafluoronaphthalene (stoichiometry 2:1, complex 5) were prepared followed by XRD characterization. In the crystal lattice of 1, face-to-face and face-to-edge Ph_H/Ph_F orientations of neighboring rings were observed together with face-to-edge Ph_F/Ph_F orientations. For the face-to-face Ph_H/Ph_F orientation, the large offset of Ph_H and Ph_F groups excludes their π-stacking interaction which is very non-typical of the field. The crystal lattice of 4 reveals standard π-stacking interactions of the arene-polyfluoroarene type. While in the lattice of 4 each Ph_F ring interacts alternating with naphthalenes, in 5 two disulfides 3 are bridged by one octafluoronaphthalene with only one of the Ph_H rings of each disulfide interacting with the polyfluoroarene π-system. The large offset of neighboring molecules excludes however their π-stacking interactions in complex 5. An attempt to prepare 2/3 co-crystals failed.     

Supramolecular assembly of three d10 metal coordination polymers based on the naphthalene-1,8-dicarboxylate ligand: Syntheses, structures and luminescent properties

Three d¹⁰ tetranuclear complexes, [Cd₄(1,8-nap)4(2,2′-bipy)₄(H₂O)8]·6H₂O (1,8-nap = naphthalene-1,8-dicarboxylate and 2,2′-bipy = 2,2′-bipyridine) (1), [Cd₄(1,8-nap)4(2,2′-bipy)₄(H₂O)8]·6H₂O (2) and [Zn₄(1,8-nap)₄(2,2′-bipy)₄(H₂O)4]·2H₂O (3), have been synthesized under hydrothermal conditions and characterized by elemental analyses, IR and X-ray diffraction techniques. Complexes 1 and 2 are isomers showing one-dimensional ribbon-like structures connected by O-H…O hydrogen bonds, and the one-dimensional ribbons are further linked into the three-dimensional network by π-π stacking. In complex 3, the intramolecular O-H…O hydrogen bonds just exist in the inner of the single molecule ring to consolidate its structure, and the single molecules are further linked into a two-dimensional layer structure by the π-π stacking interactions. The luminescent properties reveal that all the complexes display luminescent properties in the violet region.     

Coordination chemistry of anticrowns. Complexation of cyclic trimeric perfluoro-o-phenylenemercury (o-C6F4Hg)3 with compounds containing an active methylene group

The reactions of three-mercury anticrown (o-C₆F₄Hg)₃ (1) with acetoacetic ester (AE), malonic ester (ME), and malonodinitrile (MN) afford 1: 1 complexes {[(o-C₆F₄Hg)₃](AE)} (3), {[(o-C₆F₄Hg)₃](ME)} (4), and {[(o-C₆F₄Hg)₃](MN)} (5). The structures of complexes 3–5 were determined by X-ray diffraction analysis. Complex 3 has a discrete structure in the solid state, whereas complexes 4 and 5 form in the crystal extended stacks representing polydecker sandwiches with alternating molecules of 1 and ME or MN. According to the X-ray diffraction and IR spectral data, the molecule of AE in complex 3 is in the keto form.     

Coordination chemistry of anticrowns: Complexation of cyclic trimeric perfluoro-o-phenylenemercury with nitro compounds

Cyclic trimeric perfluoro-o-phenylenemercury (o-C₆F₄Hg)₃ (1) is capable of reacting with nitromethane to give complex {[(o-C₆F₄Hg)₃](CH₃NO₂)} (2) containing one molecule of the nitro compound per one macrocycle molecule. In this complex, the nitromethane ligand is bound to 1 by its both oxygen atoms, one of which is simultaneously coordinated to all three Hg centres of the macrocycle while the other interacts with a single Hg centre. The complex of similar composition, {[(o-C₆F₄Hg)₃](C₆H₅NO₂)} (3), is produced in the interaction of 1 with nitrobenzene. In this complex too, the both oxygen atoms of the nitro group are involved in the bonding to the macrocycle. A distinctive feature of 3 is that here one oxygen atom of the coordinated nitro derivative is bound by only two Hg centres of 1 whereas the other interacts again with a single Hg site. The reaction of 1 with 5-nitroacenaphthene affords a 1:1 complex, {[(o-C₆F₄Hg)₃](C₁₂H₉NO₂)} (4), having a polydecker sandwich structure in the crystal. Unlike in 3, the aromatic rings of the nitroarene units in 4 are disposed virtually in parallel to the macrocycles. The nitro compound in 4 behaves again as a bidentate ligand, forming three Hg-O bonds with one of the adjacent macrocycles and a single Hg-O bond with another molecule of 1. The complex is characterized also by shortened Hg-C contacts between the Hg centres of 1 and the carbon atoms of the nitroarene moiety as well as shortened C-C contacts between the carbon atoms of the nitroarene and the macrocycle. In the interaction of 1 with 1-nitropyrene, complexes of two compositions, viz. {[(o-C₆F₄Hg)₃](C₁₆H₉NO₂)} (5) and {[(o-C₆F₄Hg)₃](C₁₆H₉NO₂)₃} (6) are formed. An X-ray diffraction study of 6 has shown that in this adduct two of three coordinated molecules of the nitro compound are located on one side of the metallacycle plane while the third nitroarene molecule is disposed on its other side. The aromatic rings of all three nitropyrene ligands in 6 are practically parallel to the mean plane of the macrocycle. In contrast to 2-4, each molecule of the nitroarene in 6 is bonded to 1 by a single oxygen atom which is coordinated only to one Hg centre. In the case of one of the nitropyrene ligands that forms much longer Hg-O bond with 1 than two others, an additional contribution to the bonding is made by shortened Hg-C contacts between the macrocycle and the carbon atoms of the aromatic pyrene core and also by shortened C-C contacts between the carbon atoms of the coordinated nitroarene and 1. The synthesized adducts are the first examples of complexes of an anticrown with nitro compounds.     

The syntheses and structures of two silver compounds based on Phdat

Based on the organic ligand 2,4-diamine-6-phenyl-1,3,5-triazine (Phdat), two Ag(I) compounds, Ag(Phdat)₂(NO₃) (I) and Ag(Phdat)₂(OAc) (II), have been synthesized and characterized by single crystal X-ray diffractions, elemental analyses, and IR spectra. Compounds I and II are mononuclear and binuclear structures, respectively, and with the help of N-H…O and N-H…N hydrogen bonds and π…π packing interactions, the 3D supramolecular networks are built up.     

Influence of intermolecular interactions on the conformation of a 2-[bis(2-ethylphenyl)thiophosphorylhydroxymethyl]-1-ethylbenzimidazole molecule (L) upon complex formation with ZnCl2: Crystal and molecular structures of molecule L

The structures and conformations of a 2-[bis(2-ethylphenyl)thiophosphorylhydroxymethyl]-1-ethylbenzimidazole (L) molecule in the free form (L_fr) and in the [ZnCl₂L]L complex (I) are compared using the X-ray diffraction data. In complex I, one ligand molecule (L_c) is coordinated to the zinc atom in the bidentate chelating mode and the second molecule (L_solv) accomplishes the solvating function. An isomer with the cis orientation of the O(1) atom to the N(1) atom is observed in the crystal structure of L_fr, like L_solv in complex I, with the formation of the five-membered corrugated H-heterocycle OC₂NH. L_fr and L_solv molecules differ in the arrangement of the aromatic rings of the 2R substituent of benzimidazole. Crystalline compound L forms dimeric associates in which three conjugate H-rings are closed by a bifurcate intermolecular hydrogen bond: two five-membered ONC₂H rings and one planar four-membered N₂H₂ ring ((N(1)…N(1A), 3.705 and H(1)…H(1A) 2.67 Å). Unlike crystals of compound I with the π-π-stacking interaction between the planar-parallel aromatic rings of benzimidazole of the L_solv and L_c molecules, the crystals of L have no similar interaction between the L_fr molecules.     

Hydrothermal synthesis, crystal structure, and photoluminescence of Pb(II) and Mn(II) coordination polymers based on imidazo[4,5-f][1,10]phenanthroline

Two new coordination polymers, [Pb(IDPT)₂(NO₃)₂] (I) and [Mn(IDPT)(SO₄)(H₂O)₂] (II) (IDPT = imidazo[4,5-f][1,10]phenanthroline), were synthesized by hydrothermal method and characterized by elemental analysis and single-crystal X-ray diffraction technique. The results reveal that the complex I belongs to monoclinic crystal system, space group C2/c and complex II belongs to monoclinic crystal system, P2₁/c space group. The cell parameters are: a = 19.1970(13), b = 7.3875(5), c = 17.3825(12) Å, β = 100.47(10)°, V = 2424.0(3) ų, Z = 4, F(000) = 1488 for I; a = 10.9135(6), b = 7.0230(4), c = 19.7034(10) Å, β = 99.32(10)°, V = 1490.25(14) ų, Z = 4, F(000) = 828 for II. In the structure of complex I, the metal center Pb(II) is six-coordinated, displays an octahedral geometry. Each molecule is further connected with neighboring one via π-π interactions into 1D chain. In complex II, Mn(II) is six-coordinated to form a distorted octahedral geometry. Compound II displays 1D supramolecular chain formed through hydrogen bonds. Additionally, the fluorescent properties for the complexes were investigated. Complexes I and II exhibit strong photoluminescence with emission maximum at 583 and 529 nm at room temperature.     

Hydrothermal synthesis, crystal structure, and luminescence of a novel tetranuclear zinc(ii) complex

A new tetranuclear zinc(II) complex [Zn₄(tmphen)₄(tbip)₄(H₂O)₄] (1, tmphen = 3,4,7,8-tetramethyl-1,10-phenanthroline, H₂tbip = 5-tert-butyl isophthalic acid) is hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction, elemental analysis, and IR spectroscopy. In complex 1, four tbip^2? ligands act as bridges between four neighboring Zn atoms to form an unusual tetranuclear zinc cluster. The clusters are further connected by two types of O-H…O and C-H…O hydrogen bonds, generating a three-dimensional supramolecular structure. Meanwhile, π-π stacking interactions and C-H…π interactions further consolidate the three-dimensional supramolecular framework of 1. In addition, the luminescence measurements reveal that complex 1 exhibits strong fluorescent emissions in the solid state at room temperature.     

Reactions of ytterbium(II) bis(indenyl) complex (C9H7)2Yb(thf)2 with 2,2’-bipyridine and 1,4-bis(2,6-diisopropylphenyl)-1,4-diazabuta-1,3-diene. Structures and properties of (C9H7)2Yb(bipy) and (C9H7)2Yb(2,6-Pri 2C6H3NCHCHNC6H3Pri 2-2,6) complexes

The reaction of the ytterbium(II) bis(indenyl) complex (C₉H₇)₂Yb(thf)₂ (1) with 2,2’-bipyridine afforded the diamagnetic (C₉H₇)₂Yb(bipy) compound (2), whose structure was established by X-ray diffraction analysis. Under similar conditions, the reaction of complex 1 with 1,4-bis(2,6-diisopropylphenyl)-1,4-diazabuta-1,3-diene (DAD) led to oxidation of ytterbium giving rise to the paramagnetic (C₉H₇)₂Yb(DAD) complex (3). Magnetic measurements, X-ray diffraction study, and ¹H NMR spectroscopy in benzene confirmed the trivalent state of the ytterbium atom and the radical-anionic nature of the diazadiene ligand in complex 3. In the complex 3—solvent system, the oxidation state of metal depends on the coordination ability of the solvent. In benzene, complex 3 exists as (C₉H₇)₂Yb^III(DAD^·-), whereas (C₉H₇)₂Yb^II(thf)₂ and DAD⁰ are present in THF.     

Guest inclusion in cyclic imides containing flexible tethers

Guest inclusion properties of two cyclic imides which have carboxylic acids connected through flexible tether, namely, 4-(1,3-dioxo-1,3-dihydro-isoindol-2-ylmethyl)-cyclohexanecarboxylic acid (1) and 4-(1,3-dioxo-1H,3H-benzo[de]isoquinolin-2-ylmethyl)-cyclohexanecarboxylic acid (2) are studied. The crystals of host 1 containing one molecule of 1, the crystals of 4,4′-bipyridine (bpy) cocrystal of 1 containing one molecule of 1 and half molecule of bpy (1a), the crystals of 1,4-dioxane solvate of 1 containing two molecule of 1 and one and half molecule of 1,4-dioxane (1b) and the crystals of quinoline solvate of 1 containing one molecule of 1 and one molecule of quinoline (1c) in their crystallographic asymmetric units are investigated. Intermolecular hydrogen bonded two dimensional (2D) sheet structure of 1 and 3D channel network of 1b are comprised of cyclic R ₂ ² (8) hydrogen bond motifs; whereas cleavage of dimeric carboxylic acid R ₂ ² (8) motifs occurs in the structures of 1a and 1c in which 3D host–guest networks are comprised of discrete O–H···N and cyclic R ₂ ² (7) interactions, respectively. Various types of weak interactions between the two symmetry nonequivalent host molecule are found to be responsible for the formation of channels (14 × 11 Å) filled by guest 1,4-dioxane molecules in the crystal lattice of 1b. Two different solvates of 2 containing one molecule of 2 with a water molecule (2a) and one molecule of 2 with a quinoline molecule (2b) in their crystallographic asymmetric units, respectively, are also crystallized in different space groups. The quinoline molecules are held with host molecules by discrete O–H···N and C–H···O interactions and reside inside the voids formed by 3D repeated hexameric assemblies of host molecules in the crystal lattice of 2b.     

Synthesis and crystal structures of two new Schiff base cobalt(II) and nickel(II) complexes

The Schiff base ligand (HL) obtained from phenylmethanamine and 5-methoxysalicylaldehyde are used as ligands for Co(II) and Ni(II) resulting in complexes [Co(L)₂] (I) and [Ni(L)₂] (II), and their solid state structures were determined by X-ray crystallography. In both complexes, weak interactions play an important role in the molecular self-assembly. Complex I was stacked up to the 2D layers by C-H…O hydrogen bonds and C-H…π interactions. In contrast, complex II was extended into 2D sheet by C-H…O hydrogen bonds, the C-H…π interactions, and edge-to-face interactions.     

Ni(II) complexes with optically active bis(menthane), pinano-para-menthane ethylenediaminodioximes and pinano-para-menthane, bis(pinane) propylenediaminodioximes: Synthesis, structures, and properties

Reactions of Ni(NO₃)₂ · 6H₂O) in EtOH(iso-PrOH) with optically active bis(menthane) ethylene-diaminodioxime (H₂L¹), pinano-para-menthane ethylenediaminodioxime (H₂L²), pinano-para-menthane propylenediaminodioxime (H₂L³) and bis(pinane) propylenediaminodioxime (H₂L⁴) were used to synthesize [Ni(H₂L¹)NO₃[NO₃ · 2H₂O (I), [Ni(HL²)]NO₃ (II), [Ni(HL³)]NO₃ (III), and [Ni(HL⁴)]NO₃ (IV). X-ray diffraction study of paramagnetic complex I (μ_eff = 3.04 μB and diamagnetic complexes II and III revealed their ionic structures. A distorted octahedral polyhedron N₄O₂ in the cation of complex I is formed by the N atoms of tetradentate cycle-forming ligand, i.e., the H₂L¹ molecule, and the O atoms of the NO ₃ ^? anion acting as a bidentate cyclic ligand. In the cations of complexes II and III, containing a pinane fragment, the coordination core NiN₄ has the shape of a distorted square formed on coordination of tetradentate cycle-forming ligands, i.e., anions of the starting dioximes. The structure of diamagnetic complex IV is likely to be similar to the structures of complexes II and III.     

Titanium complexes with novel triaryl-substituted phosphinimide ligands: Synthesis, structure and ethylene polymerization behavior

A series of titanium phosphinimide complexes [Ph₂P(2-RO-C₆H₄)]₂TiCl₂ (7, R = CH₃; 8, R = CHMe₂) and [PhP(2-Me₂CHO-C₆H₄)][THF]TiCl₃ (9) have been prepared by reaction of TiCl₄ with the corresponding phosphinimines under dehalosilylation. The structure of complex 9 has been determined by X-ray crystallography, and a solvent molecule THF was found to be coordinated with the central metal and the Ti-O bond was consistent with the normal Ti-O (donor) bond length. The complexes 7 and 8 displayed inactive to ethylene polymerization, and the complex 9 displayed moderate activity in the presence of modified methylaluminoxane (MMAO) or i-Bu₃Al/Ph₃CB(C₆F₅)₄, and this should be partly attributed to coordination of THF with titanium and the steric effect of two iso-propoxyl. And catalytic activity up to 32.2 kg-PE/(mol-Ti h bar) was observed.     

Synthesis and crystal and molecular structures of new copper and zinc complexes with aza-14-crown-4 ether having di(α-pyridyl)-substituted bispidine subunit

The complexes [Cu(L)(H₂O)](ClO₄)₂ · 2H₂O (I) and [Zn(L)Cl₂] · C₂H₅OH (II), where L is the macrocyclic substituted aza-14-crown-4 ether molecule containing di(α-pyridyl)bispidine insert, were synthesized and studied by X-ray diffraction. The Cu atoms in complex I and the Zn atoms in complex II have equal coordination numbers of 5 and different highly distorted polyhedra (the CuN₄O tetragonal pyramid and ZnN₃Cl₂ trigonal bipyramid). Ligand L in structure I performs the tetradentate tetrachelate (4N) structural function and in II, it performs the tridentate bis-chelate (3N) function. The key difference between the structures of complexes I and II is determined by different conformations of both the aza-macrocycles and bispidine substituents of ligand L.     

Synthesis and reactivity of bis(heptamethylindenyl) yttrium (Ind*2Y) complexes containing alkyl and hydride ligands: crystal structure of Ind*2YCl(THF)

The syntheses and reactivities of yttrium alkyl and hydride complexes containing a sterically demanding, bis(heptamethylindenyl) ligand set are reported. The chloride complex Ind*₂YCl(THF) (2, Ind* = heptamethylindenyl) was prepared by the reaction of Ind*Na (1, 2 equiv) with YCl₃ in THF. Compound 2 was structurally characterized. Complex reaction mixtures were obtained when compound 2 was treated with KSi(SiMe₃)₃ or (THF)₃LiSi(SiMe₃)₃, although 2 reacted readily with MeLi to yield the methyl complex Ind*₂YMe(THF) (3). Treatment of 3 with H₂ or PhSiH₃ gave the base-stabilized hydride complex Ind*₂YH(THF) (4). The base-free chloride complex Ind*₂YCl (5) was synthesized by the reaction of 1 (2 equiv) with YCl₃ in toluene. Treatment of 2 with LiCH(SiMe₃)₂ yielded the base-free alkyl complex Ind*₂YCH(SiMe₃)₂ (6). No reaction was observed between 6 and CH₄, and complex reaction mixtures were obtained when 6 was treated with H₂ or PhSiH₃. However, when 6 was treated with H₂ in the presence of THF, the transient hydride Ind*₂YH was trapped as complex 4. The increased steric bulk of 6 leads to a slower reaction with PhSiH₃ as compared to Cp*₂YCH(SiMe₃)₂ (7).     

Syntheses, crystal structures, and magnetic properties for two spin-ladder complexes based on bis(2-thioxo-1,3-dithiole-4,5-dithiolato)nickelate monoanion building block

Two isostructural complexes based on bis(2-thioxo-1,3-dithiole-4,5-dithiolato)nickelate monoanion ([Ni(Dmit)₂]^?) building block, (C₁₉H₁₁NNiF₃S₁₀ (I) and C₁₈H₁₀N₂F₃NiS₁₀ (II)), have been synthesized and characterized structurally and magnetically. Two complexes crystallize in monoclinic space group $P\bar 1$ with very similar cell parameters and packing structures. The planar [Ni(Dmit)₂]^? monoanions form face-to-face π-type dimer, and the neighboring dimers are aligned into a ladder-type arrangement via lateral-to-lateral S…S contacts along x axis in the crystals of I and II. Two complexes exhibit similar magnetic behaviors, and their magnetic susceptibility data can be fitted to a Heisenberg antiferromagnetic two-legged spin ladder formula in high-temperature region and reproduced well by the Troyer expression in low-temperature region. The spin-gap values, obtained, respectively, from the fits of magnetic susceptibility data in high- and low-temperature regions, are closed to each other, indicating the chose magnetic exchange model and the results of fits are reasonable.