Crystal Forms of Hexafluorophosphate Organometallic Salts and the Importance of Charge-Assisted C−H---F Hydrogen Bonds

Grepioni, Fabrizia; Cojazzi, Gianna; Draper, Sylvia M.; Scully, Noelle; Braga, Dario

doi:10.1021/om9706626

Cited by 174 publications

(126 citation statements)

References 37 publications

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“…The infinite columns arranged in a hexagonal array are interconnected by relatively weak C5ÀH···F14 (HÀF14 2.503 ), C42ÀH···O2 (HÀO2 2.420 ) and C42ÀH···O5 (HÀ O5 2.566 ) [17] hydrogen bonds to form a three-dimensional network (Figure 3). www.chemeurj.org AgC CC 6 H 5 ·3 AgCF 3 CO 2 ·CH 3 CN (2): In an attempt to achieve an ordered arrangement of the aromatic rings of phenylacetylide ligands in a supramolecular assembly, the quaternary ammonium salt (BzMe 3 N)BF 4 (Bz = benzyl) was introduced as an additive in crystallization, with the anticipation that its benzyl group would serve as a p-p induction template.…”

Section: Resultsmentioning

confidence: 99%

Novel μ₅‐Coordination Modes of Aryl and Alkyl Ethynides and Classification of Metal–Ligand Interactions in Silver(I) Complexes

Zhao

Wong

Mak

2006

Chemistry A European J

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Novel mu(5)-eta(1),eta(1),eta(1),eta(1),eta(2) and mu(5)-eta(1),eta(1),eta(1),eta(2),eta(2) coordination modes of alkyl and aryl ethynide moieties are found in silver(I) complexes 1-5, and the metal-ligand distances can be classified into sigma, pi and mixed (sigma,pi) types. With the consistent square-pyramidal capping Ag(5) baskets of the ethynide moiety as supramolecular synthons, a series of two- and three-dimensional coordination networks are obtained.

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Section: Resultsmentioning

confidence: 99%

Novel μ₅‐Coordination Modes of Aryl and Alkyl Ethynides and Classification of Metal–Ligand Interactions in Silver(I) Complexes

Zhao

Wong

Mak

2006

Chemistry A European J

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“…This is an unusual arrangement of ligands in M 2 L 3 complexes, and is similar to the structure of the Fe(III) complex of the tetradentate siderophore alcilagin (31) , however, there are close contacts between the fluorine atoms and the CH 2 spacers of the ligands, with nonbonded C⅐⅐⅐F separations in the range 3.01-3.21 Å (and F⅐⅐⅐H contacts in the range 2.3-2.6 Å), indicative of C-H⅐⅐⅐F hydrogenbonding interactions (33,34), which no doubt help to stabilize the assembly. In addition, multiple stacking interactions between overlapping aromatic fragments of adjacent ligands are evident.…”

Section: Resultsmentioning

confidence: 54%

“…7b). These distances are characteristic of C-H⅐⅐⅐F hydrogen bonds (33,34), and the number of such interactions (three per F atom, or 12 per cage) presumably contributes significantly to stabilization of the cage structure. From the space-filling view in Fig.…”

Section: Resultsmentioning

confidence: 99%

Anion-templated self-assembly of tetrahedral cage complexes of cobalt(II) with bridging ligands containing two bidentate pyrazolyl-pyridine binding sites

Paul

Bell²,

Jeffery³

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

145

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The bridging ligands L 1 and L 2 contain two N,N-bidentate pyrazolyl-pyridine units linked to a central aromatic spacer unit (1,2-phenyl or 2,3-naphthyl, respectively). Reaction with Ni(II) salts and treatment with the anions tetrafluoroborate or perchlorate result in formation of dinuclear complexes having a 2:3 metal:ligand ratio, with one bridging and two terminal tetradentate ligands. In contrast, reaction of L 1 and L 2 with Co(II) salts, followed by treatment with tetrafluoroborate or perchlorate, results in assembly of cage complexes having a 4:6 metal:ligand ratio; these complexes have a metal ion at each corner of an approximate tetrahedron, and a bis-bidentate bridging ligand spanning each edge. The central cavity is occupied by a tetrahedral counterion that forms multiple hydrogen-bonding interactions with the methylene protons of the bridging ligands. The anionic guest fits tightly into the central cavity of the cage to which it is ideally complementary in terms of shape, size, and charge. Solution NMR experiments show that the central anion acts as a template for cage formation, with a mixture of Co(II) and the appropriate bridging ligand alone giving no assembly into a cage until the tetrahedral anion is added, at which point cage assembly is fast and quantitative. The difference between the structures of the complexes with Ni(II) and Co(II) illustrate how the uncoordinated anions can exert a profound influence on the course of the assembly process. Metal-directed self-assembly has recently become a major tool by which coordination chemists can prepare large and elaborate complexes such as helicates, grids, boxes, rings, and cages from relatively simple components (1-11). Many examples are based on accurate control of metal-ligand coordinate bond formation, with the course of the assembly involving a labile metal ion and a multidentate ligand dictated by the metal͞ligand interactions. This behavior is exemplified by the formation of helical complexes with linear oligopyridines, where the partitioning of the ligand into bidentate or terdentate binding domains is dictated by the preference of the metal ion for four-coordinate or six-coordinate geometry (3). Recently, however, it has become apparent that ''innocent'' anions can dictate the course of the assembly process by acting as a template around which a particular combination of metal ions and ligand can assemble in a way which would not occur in the absence of the anion. For example, Lehn and coworkers (12) showed how a trinuclear M 3 L 3 triple helicate converted to a circular M 5 L 5 helicate in the presence of chloride ion, which was tightly bound in the center of the resulting cationic cavity. Anions that are chosen for their innocence in terms of coordinating ability can nevertheless direct the course of an assembly process via noncovalent interactions.Here we describe how the anions perchlorate and tetrafluoroborate act as templates for the formation of edge-bridged tetrahedral M 4 (-L) 6 cages from Co(II) and bis-bidentate bridging ligand...

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“…Both these distances are below the sum of van der Waals radii for hydrogen and fluorine [33,34] and are typical for this type of hydrogen bonding. [39,40] These interactions build up chains that run along c axis of the unit cell. The chains are arranged into sheets by means of CϪH···π interactions, as can be seen also in Figure 5 (c) as red dotted lines.…”

Section: }Ag{ch 3 Cn}](bf 4 ) (4)mentioning

confidence: 99%

Influence of the Crystallization Solvent on Molecular and Supramolecular Structures of Silver(I) Tris(3‐Phenylpyrazolyl)methane Complexes

2003

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The compound 3 }Ag](BF 4 ) (pz = pyrazolyl ring) has been prepared and shown to crystallize in four different forms depending on the solvent. Vapor-phase diffusion of diethyl ether into nitromethane solutions of the complex produces two polymorphs, an orthorhombic form (1) and triclinic form (2). Both polymorphs are coordination polymers constructed by a κ 2 −κ 1 coordination of the tris(3-Phpz)methane units and have similar, but different, supramolecular structures. In 1 there are two independent chains linked by C−H···π interactions. In 2 only one type of chain is present, with a different internal structure than in 1. Non-covalent forces, mainly C−H···π interactions, organize the chains into sheets and the sheets into a final 3-D supramolecular struc-

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Crystal Forms of Hexafluorophosphate Organometallic Salts and the Importance of Charge-Assisted C−H---F Hydrogen Bonds

Cited by 174 publications

References 37 publications

Novel μ₅‐Coordination Modes of Aryl and Alkyl Ethynides and Classification of Metal–Ligand Interactions in Silver(I) Complexes

Novel μ₅‐Coordination Modes of Aryl and Alkyl Ethynides and Classification of Metal–Ligand Interactions in Silver(I) Complexes

Anion-templated self-assembly of tetrahedral cage complexes of cobalt(II) with bridging ligands containing two bidentate pyrazolyl-pyridine binding sites

Influence of the Crystallization Solvent on Molecular and Supramolecular Structures of Silver(I) Tris(3‐Phenylpyrazolyl)methane Complexes

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Crystal Forms of Hexafluorophosphate Organometallic Salts and the Importance of Charge-Assisted C−H---F Hydrogen Bonds

Cited by 174 publications

References 37 publications

Novel μ5‐Coordination Modes of Aryl and Alkyl Ethynides and Classification of Metal–Ligand Interactions in Silver(I) Complexes

Novel μ5‐Coordination Modes of Aryl and Alkyl Ethynides and Classification of Metal–Ligand Interactions in Silver(I) Complexes

Anion-templated self-assembly of tetrahedral cage complexes of cobalt(II) with bridging ligands containing two bidentate pyrazolyl-pyridine binding sites

Influence of the Crystallization Solvent on Molecular and Supramolecular Structures of Silver(I) Tris(3‐Phenylpyrazolyl)methane Complexes

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Novel μ₅‐Coordination Modes of Aryl and Alkyl Ethynides and Classification of Metal–Ligand Interactions in Silver(I) Complexes

Novel μ₅‐Coordination Modes of Aryl and Alkyl Ethynides and Classification of Metal–Ligand Interactions in Silver(I) Complexes