Abstract
C
4
H
2
N
3
BrO
4
·H
2
O, monoclinic,
P
2
1
/
c
(no. 14),
a
= 7.177(2) Å,
b
= 10.999(3) Å,
c
= 10.414(3) Å,
β
=
100.145
(
11
)
∘
$100.145{(11)}^{\circ }$
,
V
= 809.3(4) Å
3
,
Z
= 4,
R
...g
t
${R}_{\mathrm{g}\mathrm{t}}$
(
F
) = 0.0379,
w
R
r
e
f
$w{R}_{\mathrm{r}\mathrm{e}\mathrm{f}}$
(
F
2
) = 0.0714, T = 200 K
Abstract
C
10
H
9
BrN
2
, orthorhombic,
P
2
1
2
1
2
1
(no. 19),
a
= 5.9070(3) Å,
b
= 9.2731(7) Å,
c
= 17.5641(14) Å,
V
= 962.09(12) Å
3
,
Z
= 4,
R
gt
(
F
) = 0.0504,
wR
ref
(
F
2
) = 0.0947, ...T = 293(2) K.
Nickel acetate tetrahydrate (NAT) sample series were used to modify screen‐printed carbon electrodes (SPCE). The samples were hybrid Ni/NiO nanocomposites, where the NiO phase increased with an ...applied treatment temperature. Results of electrochemical measurements pointed that the Ni/NiO550/SPCE‐modified electrode had the best analytical performance toward the detection of riboflavin (RF). The Ni/NiO550/SPCE‐based sensor showed linear response with RF in the concentration range of 0.5–75 μM and 0.15 μM LOD in BRBS. Sensor offered fast response time, good repeatability, and selectivity with an RSD of 1.4 %. Our results show that the Ni:NiO nanocomposite ratio strongly influenced the electroanalytical performance of SPCE.
The reaction of copper(II) nitrate and pyridoxal S-methylisothiosemicarbazone (PLITSC) in the presence of ammonium thiocyanate resulted in the formation of two types of complexes. A dimeric complex ...of the formula ?Cu(?-PLITSC)NCS?2(NCS)2?2MeOH was obtained in the presence of excess of ammonium thiocyanate, while in the presence of its nearly equimolar amount, crystals of a polymeric complex ?Cu(?-PLITSC)NCSNO3?MeOH?n were formed. The complexes were characterized by elemental analysis, conductometry, IR spectroscopy, and their structures are unequivocally determined by single crystal X-ray crystallography. In both complexes, the copper atom is five-coordinated, situated in a deformed square-pyramidal environment. The basal plane of the square pyramid is defined by the oxygen atom of the deprotonated phenol group and terminal nitrogen atoms of the isothiosemicarbazide moiety of the Schiff base, as well as the nitrogen atom of the coordinated thiocyanate ion, while the apical site is occupied by the oxygen atom of the hydroxymethyl group of the neighboring asymmetric unit. This coordination mode of the PLITSC was hitherto unknown. A survey of the Cambridge Structural Database showed that the coordination of the hydroxymethyl group is rare within pyridoxal-based Schiff base metal complexes.
Abstract
C
18
H
12
Br
2
CuN
4
O
2
, monoclinic,
P
2
1
/
c
(no. 14),
a
= 11.5165(11) Å,
b
= 5.4369(5) Å,
c
= 14.4872(14) Å,
V
= 873.52(14) Å
3
,
Z
= 2,
R
gt
(
F
) = 0.0232,
wR
ref
(
F
2
...) = 0.0559,
T
= 200 K.
Pyrazole-type complexes with Ni(II) and Cu(II) Jaćimović, Željko K; Giester, Gerald; Kosović, Milica ...
Journal of thermal analysis and calorimetry,
02/2017, Volume:
127, Issue:
2
Journal Article
Peer reviewed
New nickel(II) and copper(II) coordination compounds were synthesized by the reaction of N-(benzyloxycarbonyl)-1H-pyrazole-1-carboxamidine ligand (HL) with Ni(II) and Cu(II) acetate in methanolic ...solution. The crystal and molecular structures of the complexes as well as those of the ligand were determined by single-crystal X-ray structure analysis. The octahedral surrounding around the metal centers in the isostructural complexes ML2(MeOH)2, M = Ni(II), Cu(II), MeOH = methanol, is established by the bidentate coordination of two ligand molecules through the pyrazole nitrogen and the deprotonated nitrogen atom of the carboxamidine group along with the oxygen atoms from two MeOH molecules. Despite that the molecular structure of the complexes was determined by X-ray structure analysis, in the FT-IR spectra of the compounds the characteristic bands for MeOH were missing. By coupled TG–MS measurements, it was found that compounds during the transport and storage exchanged MeOH by water molecules. The amount of the water was calculated on the basis of thermogravimetric data. The antifungal activity of the compounds was tested against fungi Ph. viticola and B. dothidea and compared to that of a commercial fungicide. Depending on the fungi and on the structure, the compounds showed different, but somewhat lower activity than the commercial fungicide.
Abstract
C
7
H
7
F
3
N
2
O
2
, monoclinic,
P
2
1
/
m
(no. 11),
a
= 6.8088(8) Å,
b
= 6.7699(9) Å,
c
= 9.9351(12) Å,
β
= 105.416(3)°,
V
= 441.48(9) Å
3
,
Z
= 2,
R
gt
(
F
) = 0.0398,
wR
ref
(
F
2
) = ...0.1192,
T
= 200(2) K.
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