A new coordination polymer formulated as C
8H
10CdO
7
n
·4H
2O has been prepared via a hydrothermal procedure by using 1,4-benzenedicarboxylic (p-BDC) and Cd
II salt as starting materials. The ...structure was determined by single-crystal X-ray diffraction and the result shows that the complex crystallizes in orthorhombic system, space group
Pcca, with
M
r=402.62,
a=7.293(2)
Å,
b=9.980(3)
Å,
c=19.889(6)
Å,
V=1447.6(8)
Å
3,
Z=4,
D
c=1.847
g/cm
3,
F(000)=808,
μ(Mo
Kα)=1.559
mm
−1,
R=0.0478, w
R=0.1150, GOF=1.199. It displays a neutral layered framework along
ab plane constructed by hydrogen-bonding interaction through infinite zigzag chains. Its thermal decomposition and solid-state transformation course between 30 and 550
°C was recorded by TG curve and XRD pattern, respectively. Interestingly, it is found that at higher temperature the crystal material was converted to uniform CdO nanowires, suggesting an effective and reasonable complex-precursor procedure for preparing one-dimensional crystalline nanomaterials.
1D CdO nanowires have been prepared by an effective and reasonable complex-precursor procedure, in which a layered metal-organic framework assembled by 1D infinite zigzag chains was heated in the presence of oxygen at higher temperature.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Understanding energy transfer mechanisms in graphene derivatives is strongly motivated by the unusually interesting electronic properties of graphene, which can provide a template for the creation of ...novel nanostructured derivatives. From a synthetic point of view, it is highly attractive to envision being able to synthesize pristine graphene from precursors such as graphene oxide (GO). While this goal may be challenging over large length-scales, it is possible to generate regions of graphene at the nanoscale, confirmed by Raman spectroscopy or other methods. We describe an
in situ
method of nucleating gold or palladium nanoparticles in the presence of ethylene glycol as a reducing agent, while simultaneously reducing GO to graphene. The Au nanoparticles aid in spectroscopic characterization by both quenching fluorescence, allowing the graphene D and G bands to be quantified, and yielding a surface enhancement of about two orders of magnitude. We observe the excitation profile (488-785 nm) of the surface enhanced Raman spectrum (SERS) of graphene with Au nanoparticles adsorbed on the surface. Both the D and G bands display a resonance at approximately 593 nm (2.09 eV). This resonance may be interpreted as a combination of the plasmon resonance at 548 nm and a likely contribution from charge transfer as well. In addition, we observe a stiffening of the G band compared with that of graphene. The mechanism of the SERS, whether plasmonic or charge transfer-based, enables insight into the electronic pathways available to the graphene-nanoparticle system. We discuss our results in the context of several existing studies of graphene-based nanostructure derivatives.
We examine the SERS excitation profile for graphene with Au nanoparticles attached by means of chemical reduction. A charge-transfer resonance is observed at 2.09 eV.
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IJS, KILJ, NUK, UL, UM, UPUK
We report surface-enhanced Raman scattering (SERS) spectra from 4-mercaptopyridine (4-Mpy) adsorbed on sub-monolayers of -Fe2O3 nanocrystals (sphere, spindle, cube). The maximum enhancement factor ...has been estimated to be about 104 compared to that of 4-Mpy in solution. A possible mechanism has been proposed that the charge transfer between the -Fe2O3 nanocrystals and the 4-Mpy molecules is most likely responsible for the observed enhancement of Raman intensity of adsorbed 4-Mpy molecules as surface plasmon resonances have not occurred.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The temperature tuning effect in coordination reaction with the oligomer ligand, sodium
N-(4-
O-phenyldithiocarboxylate) maleimide
n
(
n
=
10–15), has been studied. It is found that more Ti–S ...coordination bonds have been formed with reaction temperature increasing, which results in the variations in crystallinity, morphology and solid fluorescence of the prepared complex materials. The nature of temperature tuning is to improve the activity of oligomer ligands and increase the contacting probability between Ti(IV) and –CS
2 groups. Based on the experiment results, a Ti–S tetrahedral coordination model is also proposed for this case.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Two-dimensional (2-D) α-Fe
2O
3 monolayers have been successfully prepared by assembling of single-crystalline α-Fe
2O
3 nanospheres onto the surfaces of quartz slides. Hexamethylene diisocyanate ...(HDI) has been used as “bridge” to link between quartz surface and single-crystalline α-Fe
2O
3 nanospheres. The resulting monolayers have been characterized by transmission electron microscopy (TEM) and scan electron microscopy (SEM), and the correlated surface-enhanced Raman scattering (SERS) effect has been investigated. It is found that the well ordered monolayers of single-crystalline α-Fe
2O
3 nanospheres can be used as nicer substrates for SERS.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Single-crystal x-ray structure determinations have been recorded at 295 K for the dithiocarbamate metal compounds Co(Et
2
dtc)
3
, Co(nPr
2
dtc)
3
, Pd(iPr
2
dtc)
2
and Pd(Et
2
dtc)
2
. The ...stability constants(K) in EtOH of dialkyldithiocarbamate metal complexes M(R
2
dtc)
n
(M=Co, Ni, Pd. R=Me, Et, iPr, nPr. n=2, 3. dtc=dithiocarbamate) are determined by UV-vis data. The stability of the metal complexes increases in the order: Co<Ni<Pd. The effects of alkyl groups on the stability of M(R
2
dtc)
2
(M=Ni and Pd) increase in the order: Me<Et<nPr<iPr, and Co(R
2
dtc)
3
decrease in the order: Et>iPr>nPr>Me. The results obtained from this study confirm that the stability due to alkyl groups may be partly attributed to changes in the residual positive charge and also partly to steric hindrance of branched alkyl-groups. The comparison between the solid and solution states shows that the M(R
2
dtc)
2
(M=Pd, Ni) complexes have similar changes in M-S distance and stability with change in alkyl group. M(iPr
2
dtc)
2
has the shortest M-S distance and the highest stability in solution.
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BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
In the title compound, C14H10N2O2·2H2O, the water molecules are involved in hydrogen bonds and interactions. Intermolecular and intramolecular O—H⃛O hydrogen bonds connect the complex into chains ...along the a axis, whereas N—H⃛O intermolecular hydrogen bonds and C—H⃛O interactions interconnect these layers forming a three‐dimensional network.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
