13 research outputs found
Synthesis and Structural Characterizations of New Coordination Polymers Generated by the Interaction Between the Trinuclear Triangular SBU [Cu<sub>3</sub>(Ī¼<sub>3</sub>āOH)(Ī¼-pz)<sub>3</sub>]<sup>2+</sup> and 4,4ā²-Bipyridine. 3Ā°
The reactions of 4,4ā²-bipyridine
with selected trinuclear
triangular copperĀ(II) complexes, [Cu<sub>3</sub>(Ī¼<sub>3</sub>-OH)Ā(Ī¼-pz)<sub>3</sub>(RCOO)<sub>2</sub>L<sub><i>x</i></sub>], [pz = pyrazolate anion, R = CH<sub>3</sub>(CH<sub>2</sub>)<sub><i>n</i></sub> (2 ā¤ <i>n</i> ā¤
5); L = H<sub>2</sub>O, MeOH, EtOH] yielded a series of 1D coordination
polymers (CPs) based on the repetition of [Cu<sub>3</sub>(Ī¼<sub>3</sub>-OH)Ā(Ī¼-pz)<sub>3</sub>] secondary building units joined
by bipyridine. The CPs were characterized by conventional analytical
methods (elemental analyses, ESI-MS, IR spectra) and single crystal
XRD determinations. An unprecedented 1D CP, generated through the
bipyridine bridging hexanuclear copper clusters moieties, two 1D CPs
presenting structural analogies, and two monodimensional tapes having
almost exactly superimposable structures, were obtained. In one case,
the crystal packing makes evident the presence of small, not-connected pores, accounting for ca.
6% of free cell volume
Interaction of the Trinuclear Triangular Secondary Building Unit [Cu<sub>3</sub>(Ī¼<sub>3</sub>āOH)(Ī¼-pz)<sub>3</sub>]<sup>2+</sup> with 4,4ā²-Bipyridine. Structural Characterizations of New Coordination Polymers and Hexanuclear Cu<sup>II</sup> Clusters. 2Ā°
By reacting 4,4ā²-bipyridine
(bpy) with selected trinuclear
triangular Cu<sup>II</sup> complexes, [Cu<sub>3</sub>(Ī¼<sub>3</sub>-OH)Ā(Ī¼-pz)<sub>3</sub>Ā(RCOO)<sub>2</sub>Ā(LLā²)] [pz = pyrazolate anion; R = CH<sub>3</sub>, CH<sub>3</sub>CH<sub>2</sub>, CH<sub>2</sub>ī»CH, CH<sub>2</sub>ī»CĀ(CH<sub>3</sub>); L, Lā² = Hpz, H<sub>2</sub>O, MeOH] in MeOH, the
substitution of monotopic ligands by ditopic bpy was observed. Depending
on the stoichiometric reaction ratios, different compounds were isolated
and structurally characterized. One- and two-dimensional coordination
polymers (CPs), as well as two hexanuclear Cu<sup>II</sup> clusters
were identified. One of the hexanuclear clusters self-assembles into
a supramolecular three-dimensional structure, and its crystal packing
shows the presence of two intersecting channels, one of which is almost
completely occupied by guest bpy, while in the second one guest water
molecules are present. This compound also shows a reversible, thermally
induced, single-crystal-to-single-crystal transition
Platinum(II) Complexes with Novel Diisocyanide Ligands: Catalysts in Alkyne Hydroarylation
A series of novel diisocyanide ligands
(<i>o</i>-CNC<sub>6</sub>H<sub>4</sub>O)<sub>2</sub>Y (diNC-1:
Y = PĀ(O)ĀPh; diNC-2:
Y = <i>o</i>-CĀ(O)ĀC<sub>6</sub>H<sub>4</sub>CĀ(O); diNC-3:
Y = <i>m</i>-CĀ(O)ĀC<sub>6</sub>H<sub>4</sub>CĀ(O); diNC-4:
Y = CĀ(O)ĀC<sub>2</sub>H<sub>4</sub>CĀ(O); diNC-5: Y = <i>trans</i>-CĀ(O)ĀC<sub>2</sub>H<sub>2</sub>CĀ(O)) was successfully synthesized
by reaction of lithium 2-isocyanophenate (generated in situ from benzoxazole
and <i>n</i>-BuLi) and a diacylic or phosphonic dichloride.
The corresponding platinumĀ(II) complexes of general formula [PtX<sub>2</sub>(diNC)]<sub>1,2</sub> (X = Cl, Me; diNC = diisocyanide ligand)
were isolated by simple substitution of 1,5-cyclooctadiene in the
starting [PtX<sub>2</sub>(COD)] complexes. The structure of the complexes,
mononuclear or dinuclear, was confirmed by single-crystal X-ray analysis.
A dinuclear complex of formula {(Ī¼-diNC)Ā[<i>cis</i>-PtCl<sub>2</sub>(PPh<sub>3</sub>)]<sub>2</sub>} could also be obtained
with the diisocyanide ligand having a rigid fumaryl bridge and consequently
the isocyanide moieties pointing in opposite directions. All the complexes
were employed as catalysts in the hydroarylation of alkynes, showing
generally good activity and selectivity toward the <i>trans</i>-hydroarylation product. With <i>N</i>-methylindole as
aromatic substrate the major product was instead a heterocycle:alkyne
2:1 adduct
Coordination Polymers Based on the Trinuclear Triangular Secondary Building Unit [Cu<sub>3</sub>(Ī¼<sub>3</sub>āOH)(Ī¼-pz)<sub>3</sub>]<sup>2+</sup> (pz = pyrazolate) and Succinate Anion
Reaction conditions (solvent, temperature, pressure)
and reagents
ratios control the formation of different products from the reactions
involving Cu<sup>II</sup>, pyrazole (Hpz), and succinate ion (Suc).
Three different coordination polymers (CPs) (one of which porous)
based on the trinuclear triangular Cu<sub>3</sub>(Ī¼<sub>3</sub>-OH)Ā(Ī¼-pz)<sub>3</sub> secondary building unit (SBU), as well
as a 1D CP based on the CuĀ(Hpz)<sub>2</sub> SBU were obtained. Moreover,
a 3D supramolecular network, formed through quite strong H-bonding
interactions involving the mononuclear CuĀ(HSuc)<sub>2</sub>(Hpz)<sub>4</sub> complex, was also synthesized when an excess of H<sub>2</sub>Suc was added
Platinum(II) Complexes with Novel Diisocyanide Ligands: Catalysts in Alkyne Hydroarylation
A series of novel diisocyanide ligands
(<i>o</i>-CNC<sub>6</sub>H<sub>4</sub>O)<sub>2</sub>Y (diNC-1:
Y = PĀ(O)ĀPh; diNC-2:
Y = <i>o</i>-CĀ(O)ĀC<sub>6</sub>H<sub>4</sub>CĀ(O); diNC-3:
Y = <i>m</i>-CĀ(O)ĀC<sub>6</sub>H<sub>4</sub>CĀ(O); diNC-4:
Y = CĀ(O)ĀC<sub>2</sub>H<sub>4</sub>CĀ(O); diNC-5: Y = <i>trans</i>-CĀ(O)ĀC<sub>2</sub>H<sub>2</sub>CĀ(O)) was successfully synthesized
by reaction of lithium 2-isocyanophenate (generated in situ from benzoxazole
and <i>n</i>-BuLi) and a diacylic or phosphonic dichloride.
The corresponding platinumĀ(II) complexes of general formula [PtX<sub>2</sub>(diNC)]<sub>1,2</sub> (X = Cl, Me; diNC = diisocyanide ligand)
were isolated by simple substitution of 1,5-cyclooctadiene in the
starting [PtX<sub>2</sub>(COD)] complexes. The structure of the complexes,
mononuclear or dinuclear, was confirmed by single-crystal X-ray analysis.
A dinuclear complex of formula {(Ī¼-diNC)Ā[<i>cis</i>-PtCl<sub>2</sub>(PPh<sub>3</sub>)]<sub>2</sub>} could also be obtained
with the diisocyanide ligand having a rigid fumaryl bridge and consequently
the isocyanide moieties pointing in opposite directions. All the complexes
were employed as catalysts in the hydroarylation of alkynes, showing
generally good activity and selectivity toward the <i>trans</i>-hydroarylation product. With <i>N</i>-methylindole as
aromatic substrate the major product was instead a heterocycle:alkyne
2:1 adduct
Coordination Polymers Based on the Trinuclear Triangular Secondary Building Unit [Cu<sub>3</sub>(Ī¼<sub>3</sub>āOH)(Ī¼-pz)<sub>3</sub>]<sup>2+</sup> (pz = pyrazolate) and Succinate Anion
Reaction conditions (solvent, temperature, pressure)
and reagents
ratios control the formation of different products from the reactions
involving Cu<sup>II</sup>, pyrazole (Hpz), and succinate ion (Suc).
Three different coordination polymers (CPs) (one of which porous)
based on the trinuclear triangular Cu<sub>3</sub>(Ī¼<sub>3</sub>-OH)Ā(Ī¼-pz)<sub>3</sub> secondary building unit (SBU), as well
as a 1D CP based on the CuĀ(Hpz)<sub>2</sub> SBU were obtained. Moreover,
a 3D supramolecular network, formed through quite strong H-bonding
interactions involving the mononuclear CuĀ(HSuc)<sub>2</sub>(Hpz)<sub>4</sub> complex, was also synthesized when an excess of H<sub>2</sub>Suc was added
Coordination Polymers Based on the Trinuclear Triangular Secondary Building Unit [Cu<sub>3</sub>(Ī¼<sub>3</sub>āOH)(Ī¼-pz)<sub>3</sub>]<sup>2+</sup> (pz = pyrazolate) and Succinate Anion
Reaction conditions (solvent, temperature, pressure)
and reagents
ratios control the formation of different products from the reactions
involving Cu<sup>II</sup>, pyrazole (Hpz), and succinate ion (Suc).
Three different coordination polymers (CPs) (one of which porous)
based on the trinuclear triangular Cu<sub>3</sub>(Ī¼<sub>3</sub>-OH)Ā(Ī¼-pz)<sub>3</sub> secondary building unit (SBU), as well
as a 1D CP based on the CuĀ(Hpz)<sub>2</sub> SBU were obtained. Moreover,
a 3D supramolecular network, formed through quite strong H-bonding
interactions involving the mononuclear CuĀ(HSuc)<sub>2</sub>(Hpz)<sub>4</sub> complex, was also synthesized when an excess of H<sub>2</sub>Suc was added
Coordination Polymers Based on the Trinuclear Triangular Secondary Building Unit [Cu<sub>3</sub>(Ī¼<sub>3</sub>āOH)(Ī¼-pz)<sub>3</sub>]<sup>2+</sup> (pz = pyrazolate) and Succinate Anion
Reaction conditions (solvent, temperature, pressure)
and reagents
ratios control the formation of different products from the reactions
involving Cu<sup>II</sup>, pyrazole (Hpz), and succinate ion (Suc).
Three different coordination polymers (CPs) (one of which porous)
based on the trinuclear triangular Cu<sub>3</sub>(Ī¼<sub>3</sub>-OH)Ā(Ī¼-pz)<sub>3</sub> secondary building unit (SBU), as well
as a 1D CP based on the CuĀ(Hpz)<sub>2</sub> SBU were obtained. Moreover,
a 3D supramolecular network, formed through quite strong H-bonding
interactions involving the mononuclear CuĀ(HSuc)<sub>2</sub>(Hpz)<sub>4</sub> complex, was also synthesized when an excess of H<sub>2</sub>Suc was added
Coordination Polymers Based on the Trinuclear Triangular Secondary Building Unit [Cu<sub>3</sub>(Ī¼<sub>3</sub>āOH)(Ī¼-pz)<sub>3</sub>]<sup>2+</sup> (pz = pyrazolate) and Succinate Anion
Reaction conditions (solvent, temperature, pressure)
and reagents
ratios control the formation of different products from the reactions
involving Cu<sup>II</sup>, pyrazole (Hpz), and succinate ion (Suc).
Three different coordination polymers (CPs) (one of which porous)
based on the trinuclear triangular Cu<sub>3</sub>(Ī¼<sub>3</sub>-OH)Ā(Ī¼-pz)<sub>3</sub> secondary building unit (SBU), as well
as a 1D CP based on the CuĀ(Hpz)<sub>2</sub> SBU were obtained. Moreover,
a 3D supramolecular network, formed through quite strong H-bonding
interactions involving the mononuclear CuĀ(HSuc)<sub>2</sub>(Hpz)<sub>4</sub> complex, was also synthesized when an excess of H<sub>2</sub>Suc was added
New Coordination Polymers and Porous Supramolecular Metal Organic Network Based on the Trinuclear Triangular Secondary Building Unit [Cu<sub>3</sub>(Ī¼<sub>3</sub>āOH)(Ī¼-pz)<sub>3</sub>]<sup>2+</sup> and 4,4ā²-Bypiridine. 1Ā°
The
trinuclear triangular Cu<sup>II</sup> complex [Cu<sub>3</sub>(Ī¼<sub>3</sub>-OH)Ā(Ī¼-pz)<sub>3</sub>(HCOO)<sub>2</sub>(Hpz)<sub>2</sub>] (Hpz = pyrazole) reacts with 4,4ā²-bipyridine (bpy) yielding
a two-dimensional (2D) waved sheets, two three-dimensional (3D) coordination
polymers (CPs), as well as a hexanuclear Cu<sup>II</sup> cluster,
depending on the reagent ratios and reaction conditions. Single crystal
X-ray diffraction (XRD) determinations point out that, while CPs crystal
structures are not porous, the hexanuclear Cu<sup>II</sup> clusters
are packed in the solid state generating a stable porous 3D supramolecular
network, where two kinds of perpendicular, hydrophobic channels (ca.
4.83 Ć 5.86 Ć
<sup>2</sup> and 4.99 Ć 4.79 Ć
<sup>2</sup>, corresponding to the 24.7% of the total crystal volume)
are present. In the āas-synthesizedā compound, channels
of one kind are empty, while the other ones are occupied by guest
bpy molecules which can be removed by soaking the crystals in suitable
solvents (benzene, toluene, <i>c</i>-hexane) maintaining
intact the crystal skeleton. Moreover, two of the above complexes
act as catalysts (or catalyst precursors) in the peroxidative oxidation
of cyclohexane