13 research outputs found
Alkali Metal Directed Assembly of Heterometallic V<sup>v</sup>/M (M = Na, K, Cs) Coordination Polymers: Structures, Topological Analysis, and Oxidation Catalytic Properties
The
reactions of [VOĀ(acac)<sub>2</sub>] with bisĀ(salicylaldehyde)-oxaloyldihydrazone
(H<sub>4</sub>L) and an alkali metal carbonate M<sub>2</sub>CO<sub>3</sub> (M = K, Na, Cs), in EtOH/H<sub>2</sub>O medium upon reflux,
resulted in the generation of three new heterometallic V<sup>V</sup>/M materials, namely the 1D [(VO<sub>2</sub>)<sub>2</sub>(Ī¼<sub>4</sub>-L)Ā{Na<sub>2</sub>(Ī¼-H<sub>2</sub>O)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>}]<sub><i>n</i></sub> (<b>1</b>), 2D [{VĀ(Ī¼-O)<sub>2</sub>}<sub>2</sub>(Ī¼<sub>4</sub>-L)Ā{K<sub>2</sub>(Ī¼-H<sub>2</sub>O)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>}]<sub><i>n</i></sub> (<b>2</b>), and
3D [{VĀ(Ī¼-O)Ā(Ī¼<sub>3</sub>-O)}<sub>2</sub>(Ī¼<sub>8</sub>-L)Ā{Cs<sub>2</sub>(Ī¼-H<sub>2</sub>O)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>}]<sub><i>n</i></sub> (<b>3</b>) coordination polymers. They were isolated as air-stable solids
and fully characterized by IR, UVāvis, <sup>1</sup>H, and <sup>51</sup>V NMR spectroscopy, ESIāMS(Ā±), elemental, thermal,
and single-crystal X-ray diffraction analyses, the latter showing
that <b>1</b>ā<b>3</b> are constructed from the
resembling [(VO<sub>2</sub>)<sub>2</sub>(Ī¼<sub>4/8</sub>-L)]<sup>2ā</sup> blocks assembled by the differently bound aqua-metal
[M<sub>2</sub>(Ī¼-H<sub>2</sub>O)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]<sup>2+</sup> moieties (M = Na, K, Cs). The main distinctive
features of <b>1</b>ā<b>3</b> arise from the different
coordination numbers of Na (5), K (7), and Cs (9) atoms, thus increasing
the complexity of the resulting networks from the ladder-like 1D chains
in <b>1</b> to double 2D layers in <b>2</b>, and layer-pillared
3D framework in <b>3</b>. The topological analysis of <b>2</b> disclosed a uninodal 4-connected underlying net with a rare <b>kgm</b> [Shubnikov plane net (3.6.3.6)/kagome pattern] topology,
while <b>3</b> features a trinodal 4,7,8-connected underlying
net with an unprecedented topology. Compounds <b>1</b>ā<b>3</b> also show solubility in water (<i>S</i><sub>25Ā Ā°C</sub> ā 4ā7 mg mL<sup>ā1</sup>) and were applied
as efficient precatalysts for the homogeneous oxidation of cyclohexane
by aqueous H<sub>2</sub>O<sub>2</sub>, under mild conditions (50 Ā°C)
in MeCN/H<sub>2</sub>O medium and in the presence of an acid promoter.
Total yields (based on substrate) of cyclohexanol and cyclohexanone
up to 36% and turnover numbers (TONs) up to 5700 were achieved
Alkali Metal Directed Assembly of Heterometallic V<sup>v</sup>/M (M = Na, K, Cs) Coordination Polymers: Structures, Topological Analysis, and Oxidation Catalytic Properties
The
reactions of [VOĀ(acac)<sub>2</sub>] with bisĀ(salicylaldehyde)-oxaloyldihydrazone
(H<sub>4</sub>L) and an alkali metal carbonate M<sub>2</sub>CO<sub>3</sub> (M = K, Na, Cs), in EtOH/H<sub>2</sub>O medium upon reflux,
resulted in the generation of three new heterometallic V<sup>V</sup>/M materials, namely the 1D [(VO<sub>2</sub>)<sub>2</sub>(Ī¼<sub>4</sub>-L)Ā{Na<sub>2</sub>(Ī¼-H<sub>2</sub>O)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>}]<sub><i>n</i></sub> (<b>1</b>), 2D [{VĀ(Ī¼-O)<sub>2</sub>}<sub>2</sub>(Ī¼<sub>4</sub>-L)Ā{K<sub>2</sub>(Ī¼-H<sub>2</sub>O)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>}]<sub><i>n</i></sub> (<b>2</b>), and
3D [{VĀ(Ī¼-O)Ā(Ī¼<sub>3</sub>-O)}<sub>2</sub>(Ī¼<sub>8</sub>-L)Ā{Cs<sub>2</sub>(Ī¼-H<sub>2</sub>O)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>}]<sub><i>n</i></sub> (<b>3</b>) coordination polymers. They were isolated as air-stable solids
and fully characterized by IR, UVāvis, <sup>1</sup>H, and <sup>51</sup>V NMR spectroscopy, ESIāMS(Ā±), elemental, thermal,
and single-crystal X-ray diffraction analyses, the latter showing
that <b>1</b>ā<b>3</b> are constructed from the
resembling [(VO<sub>2</sub>)<sub>2</sub>(Ī¼<sub>4/8</sub>-L)]<sup>2ā</sup> blocks assembled by the differently bound aqua-metal
[M<sub>2</sub>(Ī¼-H<sub>2</sub>O)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]<sup>2+</sup> moieties (M = Na, K, Cs). The main distinctive
features of <b>1</b>ā<b>3</b> arise from the different
coordination numbers of Na (5), K (7), and Cs (9) atoms, thus increasing
the complexity of the resulting networks from the ladder-like 1D chains
in <b>1</b> to double 2D layers in <b>2</b>, and layer-pillared
3D framework in <b>3</b>. The topological analysis of <b>2</b> disclosed a uninodal 4-connected underlying net with a rare <b>kgm</b> [Shubnikov plane net (3.6.3.6)/kagome pattern] topology,
while <b>3</b> features a trinodal 4,7,8-connected underlying
net with an unprecedented topology. Compounds <b>1</b>ā<b>3</b> also show solubility in water (<i>S</i><sub>25Ā Ā°C</sub> ā 4ā7 mg mL<sup>ā1</sup>) and were applied
as efficient precatalysts for the homogeneous oxidation of cyclohexane
by aqueous H<sub>2</sub>O<sub>2</sub>, under mild conditions (50 Ā°C)
in MeCN/H<sub>2</sub>O medium and in the presence of an acid promoter.
Total yields (based on substrate) of cyclohexanol and cyclohexanone
up to 36% and turnover numbers (TONs) up to 5700 were achieved
Differentially Selective Chemosensor with Fluorescence <i>OffāOn</i> Responses on Cu<sup>2+</sup> and Zn<sup>2+</sup> Ions in Aqueous Media and Applications in Pyrophosphate Sensing, Live Cell Imaging, and Cytotoxicity
A new benzoyl hydrazone based chemosensor <b>R</b> is synthesized by Schiff base condensation of 2,6-diformyl-4-methylphenol
and phenyl carbohydrazide and acts as a highly selective fluorescence
sensor for Cu<sup>2+</sup> and Zn<sup>2+</sup> ions in aqueous media.
The reaction of <b>R</b> with CuCl<sub>2</sub> or ZnCl<sub>2</sub> forms the corresponding dimeric dicopperĀ(II) [Cu<sub>2</sub>(R)Ā(CH<sub>3</sub>O)Ā(NO<sub>3</sub>)]<sub>2</sub>(CH<sub>3</sub>O)<sub>2</sub> (<b>R-Cu</b><sup><b>2+</b></sup>) and dizincĀ(II) [Zn<sub>2</sub>(R)<sub>2</sub>]Ā(NO<sub>3</sub>)<sub>2</sub> (<b>R-Zn</b><sup><b>2+</b></sup>) complexes, which are characterized, as <b>R</b>, by conventional techniques including single-crystal X-ray
analysis. Electronic absorption and fluorescence titration studies
of <b>R</b> with different metal cations in a CH<sub>3</sub>CN/0.02 M HEPES buffer medium (pH = 7.3) show a highly selective
binding affinity only toward Cu<sup>2+</sup>and Zn<sup>2+</sup> ions
even in the presence of other commonly coexisting ions such as Na<sup>+</sup>, K<sup>+</sup>, Mg<sup>2+</sup>, Ca<sup>2+</sup>, Mn<sup>2+</sup>, Fe<sup>2+</sup>, Fe<sup>3+</sup>, Co<sup>2+</sup>, Ni<sup>2+</sup>, Cd<sup>2+</sup>, and Hg<sup>2+</sup>. Quantification of
the fluorescence titration analysis shows that the chemosensor <b>R</b> can indicate the presence of Cu<sup>2+</sup>and Zn<sup>2+</sup> even at very low concentrations of 17.3 and 16.5 ppb, respectively. <b>R-Zn</b><sup><b>2+</b></sup> acts as a selective metal-based
fluorescent sensor for inorganic pyrophosphate ion (PPi) even in the
presence of other common anions such as F<sup>ā</sup>, Cl<sup>ā</sup>, Br<sup>ā</sup>, I<sup>ā</sup>, CH<sub>3</sub>COO<sup>ā</sup>, CO<sub>3</sub><sup>2ā</sup>, HCO<sub>3</sub><sup>ā</sup>, N<sub>3</sub><sup>ā</sup>, SO<sub>4</sub><sup>2ā</sup>, PPi, AMP, ADP, and ATP in an
aqueous medium. The propensity of <b>R</b> as a bioimaging fluorescent
probe to detect Cu<sup>2+</sup> and Zn<sup>2+</sup> ions in human
cervical HeLa cancer cell lines and their cytotoxicity against human
cervical (HeLa), breast cancer (MCF7), and noncancer breast epithelial
(MCF10a) cells have also been investigated. <b>R-Cu</b><sup><b>2+</b></sup> shows better cytotoxicity and sensitivity toward
cancer cells over noncancer cells than <b>R</b> and <b>R-Zn</b><sup><b>2+</b></sup> under identical conditions, with the appearance
of apoptotic bodies
Differentially Selective Chemosensor with Fluorescence <i>OffāOn</i> Responses on Cu<sup>2+</sup> and Zn<sup>2+</sup> Ions in Aqueous Media and Applications in Pyrophosphate Sensing, Live Cell Imaging, and Cytotoxicity
A new benzoyl hydrazone based chemosensor <b>R</b> is synthesized by Schiff base condensation of 2,6-diformyl-4-methylphenol
and phenyl carbohydrazide and acts as a highly selective fluorescence
sensor for Cu<sup>2+</sup> and Zn<sup>2+</sup> ions in aqueous media.
The reaction of <b>R</b> with CuCl<sub>2</sub> or ZnCl<sub>2</sub> forms the corresponding dimeric dicopperĀ(II) [Cu<sub>2</sub>(R)Ā(CH<sub>3</sub>O)Ā(NO<sub>3</sub>)]<sub>2</sub>(CH<sub>3</sub>O)<sub>2</sub> (<b>R-Cu</b><sup><b>2+</b></sup>) and dizincĀ(II) [Zn<sub>2</sub>(R)<sub>2</sub>]Ā(NO<sub>3</sub>)<sub>2</sub> (<b>R-Zn</b><sup><b>2+</b></sup>) complexes, which are characterized, as <b>R</b>, by conventional techniques including single-crystal X-ray
analysis. Electronic absorption and fluorescence titration studies
of <b>R</b> with different metal cations in a CH<sub>3</sub>CN/0.02 M HEPES buffer medium (pH = 7.3) show a highly selective
binding affinity only toward Cu<sup>2+</sup>and Zn<sup>2+</sup> ions
even in the presence of other commonly coexisting ions such as Na<sup>+</sup>, K<sup>+</sup>, Mg<sup>2+</sup>, Ca<sup>2+</sup>, Mn<sup>2+</sup>, Fe<sup>2+</sup>, Fe<sup>3+</sup>, Co<sup>2+</sup>, Ni<sup>2+</sup>, Cd<sup>2+</sup>, and Hg<sup>2+</sup>. Quantification of
the fluorescence titration analysis shows that the chemosensor <b>R</b> can indicate the presence of Cu<sup>2+</sup>and Zn<sup>2+</sup> even at very low concentrations of 17.3 and 16.5 ppb, respectively. <b>R-Zn</b><sup><b>2+</b></sup> acts as a selective metal-based
fluorescent sensor for inorganic pyrophosphate ion (PPi) even in the
presence of other common anions such as F<sup>ā</sup>, Cl<sup>ā</sup>, Br<sup>ā</sup>, I<sup>ā</sup>, CH<sub>3</sub>COO<sup>ā</sup>, CO<sub>3</sub><sup>2ā</sup>, HCO<sub>3</sub><sup>ā</sup>, N<sub>3</sub><sup>ā</sup>, SO<sub>4</sub><sup>2ā</sup>, PPi, AMP, ADP, and ATP in an
aqueous medium. The propensity of <b>R</b> as a bioimaging fluorescent
probe to detect Cu<sup>2+</sup> and Zn<sup>2+</sup> ions in human
cervical HeLa cancer cell lines and their cytotoxicity against human
cervical (HeLa), breast cancer (MCF7), and noncancer breast epithelial
(MCF10a) cells have also been investigated. <b>R-Cu</b><sup><b>2+</b></sup> shows better cytotoxicity and sensitivity toward
cancer cells over noncancer cells than <b>R</b> and <b>R-Zn</b><sup><b>2+</b></sup> under identical conditions, with the appearance
of apoptotic bodies
A Hexanuclear Mixed-Valence Oxovanadium(IV,V) Complex as a Highly Efficient Alkane Oxidation Catalyst
The new hexanuclear mixed-valence vanadium complex [V<sub>3</sub>O<sub>3</sub>(OEt)Ā(ashz)<sub>2</sub>(Ī¼-OEt)]<sub>2</sub> (<b>1</b>) with an N,O-donor ligand is reported. It acts as
a highly
efficient catalyst toward alkane oxidations by aqueous H<sub>2</sub>O<sub>2</sub>. Remarkably, high turnover numbers up to 25000 with
product yields of up to 27% (based on alkane) stand for one of the
most active systems for such reactions
Silver(I) 1,3,5-Triaza-7-phosphaadamantane Coordination Polymers Driven by Substituted Glutarate and Malonate Building Blocks: Self-Assembly Synthesis, Structural Features, and Antimicrobial Properties
Three
new bioactive silverĀ(I) coordination polymers formulated as [Ag<sub>2</sub>(Ī¼<sub>2</sub>-PTA)Ā(Ī¼<sub>3</sub>-PTA)Ā(Ī¼<sub>2</sub>-pga)Ā(H<sub>2</sub>O)]<sub><i>n</i></sub>Ā·6H<sub>2</sub>O (<b>1</b>), [Ag<sub>2</sub>(Ī¼<sub>2</sub>-PTA)Ā(Ī¼<sub>3</sub>-PTA)<i>(</i>Hpmal)<sub>2</sub>]<i><i><sub>n</sub></i></i>Ā·2H<sub>2</sub>O (<b>2</b>), and [AgĀ(Ī¼<sub>3</sub>-PTA) (Hdmga)]<i><sub>n</sub></i> (<b>3</b>) were self-assembled from Ag<sub>2</sub>O, 1,3,5-triaza-7-phosphaadamantane
(PTA), and a substituted dicarboxylic acid (3-phenylglutaric acid
(H<sub>2</sub>pga), phenylmalonic acid (H<sub>2</sub>pmal), or 3,3-dimethylglutaric
acid (H<sub>2</sub>dmga)) as an ancillary ligand. Compounds <b>1</b>ā<b>3</b> were fully characterized by IR and
NMR spectroscopy, ESI-MS(Ā±), elemental analysis, and single-crystal
X-ray diffraction, revealing that their architectural and topological
diversity is governed by structural modulation of a dicarboxylate
building block. The structures vary from a 1D cyclic chain with the
SP 1-periodic net (4,4)Ā(0,2) topology in <b>2</b> to distinct
2D metalāorganic layers with the <b>cem-d</b> and <b>hcb</b> topologies in <b>1</b> and <b>3</b>, respectively.
In addition, compounds <b>1</b>ā<b>3</b> exhibit
a notable antimicrobial efficiency against a panel of common Gram-negative
(E. coli and P. aeruginosa) and Gram-positive (S. aureus) bacteria
and yeast (C. albicans). The best normalized
minimum inhibitory concentrations (normalized MIC) of 11ā23
nmol mL<sup>ā1</sup> (for bacterial strains) or 68 nmol mL<sup>ā1</sup> (for a yeast strain) are shown by compound <b>2</b>, and the eventual structureābioactivity correlations
are discussed
Bioactive SilverāOrganic Networks Assembled from 1,3,5-Triaza-7-phosphaadamantane and Flexible Cyclohexanecarboxylate Blocks
Three novel bioactive
silverāorganic networks, namely, the 2D polymer [AgĀ(Ī¼<sub>3</sub>-PTA)Ā(chc)]<sub><i>n</i></sub>Ā·<i>n</i>(Hchc)Ā·2<i>n</i>H<sub>2</sub>O (<b>1</b>), the
3D bioMOF [Ag<sub>2</sub>(Ī¼<sub>3</sub>-PTA)<sub>2</sub>(Ī¼<sub>2</sub>-chdc)]<sub><i>n</i></sub>Ā·5nH<sub>2</sub>O
(<b>2</b>), and the 2D polymer [Ag<sub>2</sub>(Ī¼<sub>2</sub>-PTA)<sub>2</sub>(Ī¼<sub>4</sub>-H<sub>2</sub>chtc)]<sub><i>n</i></sub>Ā·6<i>n</i>H<sub>2</sub>O (<b>3</b>), were constructed from 1,3,5-triaza-7-phosphaadamantane (PTA) and
various flexible cyclohexanecarboxylic acids as building blocks {cyclohexanecarboxylic
(Hchc), 1,4-cyclohexanedicarboxylic (H<sub>2</sub>chdc), and 1,2,4,5-cyclohexanetetracarboxylic
(H<sub>4</sub>chtc) acid, respectively}. The obtained products <b>1</b>ā<b>3</b> were fully characterized by IR and
NMR spectroscopy, ESI-MS(Ā±) spectrometry, elemental and thermogravimetric
(TGA) analyses, and single-crystal and powder X-ray diffraction. Their
structural diversity originates from distinct coordination modes of
cyclohexanecarboxylate moieties as well as from the presence of unconventional <i>N,N,P</i>-tridentate or <i>N,P</i>-bidentate PTA spacers.
Topological classification of underlying metalāorganic networks
was performed, disclosing the <b>hcb</b>, <b>4,4L28</b>, and a rare <b>fsc-3,4-<i>Pbcn</i>-3</b> topology
in <b>1</b>, <b>2</b>, and <b>3</b>, respectively.
Moreover, combination of aqueous solubility (<i>S</i><sub>25Ā°C</sub> ā 4ā6 mg mL<sup>ā1</sup>), air
stability, and appropriate coordination environments around silver
centers favors a release of bioactive Ag<sup>+</sup> ions by <b>1</b>ā<b>3</b>, which thus act as potent antibacterial
and antifungal agents against Gram-positive (<i>S. aureus</i>) and Gram-negative (<i>E. coli</i> and <i>P. aeruginosa</i>) bacteria as well as a yeast (<i>C. albicans</i>). The
best normalized minimum inhibitory concentrations (normalized MIC)
of 10ā18 (for bacterial strains) or 57 nmol mL<sup>ā1</sup> (for a yeast strain) were achieved. Detailed ESI-MS studies were
performed, confirming the relative stability of <b>1</b>ā<b>3</b> in solution and giving additional insight on the self-assembly
formation of polycarboxylate AgāPTA derivatives and their crystal
growth process
1,3-Dipolar Cycloaddition of Nitrones to Gold(III)-Bound Isocyanides
Treatment
of goldĀ(III)-isocyanides [AuCl<sub>3</sub>(CNR<sup>1</sup>)] (R<sup>1</sup> = Xyl <b>1</b>, Cy <b>2</b>, Bu<sup><i>t</i></sup> <b>3</b>) with an equimolar amount
of 5,5-dimethyl-1-pyrroline-<i>N</i>-oxide (<b>4</b>) in CH<sub>2</sub>Cl<sub>2</sub> at ā74 Ā°C leads to
the generation of the heterocyclic aminocarbene species [AuCl<sub>3</sub>{CĀ(ON<sup><i>a</i></sup>CMe<sub>2</sub>CH<sub>2</sub>CH<sub>2</sub>C<sup><i>b</i></sup>H)ī»N<sup><i>e</i></sup>R<sup>1</sup>}Ā(N<sup><i>a</i></sup>āC<sup><i>b</i></sup>)Ā(C<sup><i>b</i></sup>āN<sup><i>e</i></sup>)] <b>8</b> (for R<sup>1</sup> = Bu<sup><i>t</i></sup>) or goldĀ(III) complexes <i>cis</i>-[AuCl<sub>2</sub>{N<sup><i>a</i></sup>(CMe<sub>2</sub>CH<sub>2</sub>CH<sub>2</sub>C<sup><i>b</i></sup>N<sup><i>e</i></sup>R<sup>1</sup>)ĀC<sup><i>d</i></sup>ī»O}Ā(N<sup><i>a</i></sup>ī»C<sup><i>b</i></sup>)Ā(N<sup><i>e</i></sup>āC<sup><i>d</i></sup>)] <b>9</b> and <b>10</b> (for R<sup>1</sup> = Xyl and Cy) in
good isolated yields (75ā87%). DFT calculations show that deprotonation
of the endocyclic CH group in the carbene ligand leads to spontaneous
NāO bond cleavage, and acidity of this group is a factor controlling
the different chemical behavior of <b>1</b>ā<b>3</b> depending on the nature of substituent R<sup>1</sup>. The reaction
of equimolar amounts of the aldonitrone <i>p</i>-TolCHī»N<sup>+</sup>(Me)ĀO<sup>ā</sup> (<b>5</b>) or the ketonitrones
Ph<sub>2</sub>Cī»N<sup>+</sup>(R<sup>2</sup>)ĀO<sup>ā</sup> (R<sup>2</sup> = Ph <b>6</b>, CH<sub>2</sub>Ph <b>7</b>) with <b>1</b>ā<b>3</b> in CD<sub>2</sub>Cl<sub>2</sub> at ā70 Ā°C in air (or under N<sub>2</sub>) revealed
the formation of the carbene complexes [AuCl<sub>3</sub>{CĀ(ONMeC<sup><i>a</i></sup>H-<i>p</i>-Tol)ī»N<sup><i>b</i></sup>R<sup>1</sup>}Ā(C<sup><i>a</i></sup>āN<sup><i>b</i></sup>)] (R<sup>1</sup> = Cy <b>11</b>, Xyl <b>12</b>, Bu<sup><i>t</i></sup> <b>13</b>), [AuCl<sub>3</sub>{CĀ(ONPhC<sup><i>a</i></sup>Ph<sub>2</sub>)ī»N<sup><i>b</i></sup>R<sup>1</sup>}Ā(C<sup><i>a</i></sup>āN<sup><i>b</i></sup>)] (R<sup>1</sup> = Cy <b>14</b>, Bu<sup><i>t</i></sup> <b>15</b>), or [AuCl<sub>3</sub>{CĀ(ONĀ(CH<sub>2</sub>Ph)ĀC<sup><i>a</i></sup>Ph<sub>2</sub>)ī»N<sup><i>b</i></sup>R<sup>1</sup>}Ā(C<sup><i>a</i></sup>āN<sup><i>b</i></sup>)]
(R<sup>1</sup> = Cy <b>16</b>, Xyl <b>17</b>), as studied
by <sup>1</sup>H NMR. The reaction of <b>6</b> with <b>1</b> and of <b>7</b> with <b>3</b> did not furnish carbene
products. Compounds <b>8</b>ā<b>10</b> were characterized
by ESI-MS, IR, 1D (<sup>1</sup>H, <sup>13</sup>CĀ{H}) and 2D (<sup>1</sup>H,<sup>1</sup>HāCOSY, <sup>1</sup>H,<sup>13</sup>C-HSQC, <sup>1</sup>H,<sup>13</sup>C-HMBC) NMR spectroscopic techniques, and,
only for <b>8</b>, elemental analyses (C, H, N), while compounds <b>11</b>ā<b>17</b> were characterized by 1D (<sup>1</sup>H, <sup>13</sup>CĀ{H}) and 2D (<sup>1</sup>H,<sup>13</sup>C-HSQC)
NMR. Structures of compounds <b>8</b>, <b>9</b>, and <b>13</b> were additionally established by single-crystal X-ray diffraction
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
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