Four Cd(II) coordination polymers were generated from two isomeric expanded aromatic N,N′ donor linkers and acetate or iodide as co-ligands. X-ray diffraction revealed the decisive effect of the ...co-ligands on the coordination sphere and the topology of the products. The solids thus generated are thermally stable and show fluorescence at room temperature.
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The isomeric N donor linkers bis(pyridin-4-ylmethylene)naphthalene-1,5-diamine (L1) and bis(pyridin-3-ylmethylene)naphthalene-1,5-diamine (L2) have been used with acetate and iodide as co-ligands to generate four new cadmium(II) coordination polymers. CdL1(OAc)2n (1), CdL1(I)2n (2), CdL2(OAc)2n (3) and CdL2(I)2n (4) were characterized by elemental analysis, X-ray powder diffraction, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. In line with the concept of crystal engineering, their structures share common motifs: the heteroaromatic linkers generate chains, subtending Cd⋯Cd distances consistent with their N donor arrangement. The co-ligands control the coordination number of the Cd(II) cations and interchain connectivity: The acetate moieties either adopt bridging and chelating or exclusively bridging modes and crosslink essentially linear chains based on octahedral metal centers; in the former case, the ladder-like one-dimensional ribbon 1 is generated, whereas the latter connectivity results in the two-dimensional layer structure 3. In contrast, iodide acts as terminal ligand towards tetrahedral Cd(II), and hence 2 and 4 are single-stranded 1D zig-zag polymers. In comparison to the uncoordinated heteroaromatic L1 and L2, the Cd coordination polymers show slightly red-shifted luminescence spectra of significantly higher intensity due to the more rigid arrangement of the π systems.
The reaction of sodium phenylselenolate and copper(I) chloride generates in situ a “CuSePh” species, which can be stabilized by N, N′‐donor ligands such as bpy (2, 2′‐bipyridine) or phen (1, ...10‐phenanthroline) in order to generate compounds with μ2‐SePh– or μ3‐SePh– groups connecting the copper atoms. The intermediate stabilization of mononuclear “CuSePh” building blocks by the coordination N, N′‐donor ligands prevents from the rapid formation of less soluble polymers and gives access to three new compounds, {Cu2(bpy)2(μ3‐SePh)}{CuCl2}22, {Cu4(phen)3(μ2‐SePh)(μ3‐SePh)}2(μ2‐Cl)2 (CuCl2)2·2(PhSe)2, and Cu6(bpy)2(μ2‐SePh)2(μ3‐SePh)4·(THF).
HgX2L molecules invariably dimerize when X=Cl but this tendency decreases for X=Br and I. For the HgCl2L structures, the strength of the Hg–N(imino) bond can be diminished by increasing the ...electronegativity of the substituents in L.
A systematic series of seven mercury compounds of (E)-N-(pyridin-2-ylmethylidene)arylamine (L), where L is a variously R substituted ligand, with the formulations HgX2L2: X=Cl; R=4-CH2CH3 (4), 4-OCH2CH3 (5), 4-Cl (6), 2-CO2CH3 (7), or 4-CO2CH3 (8); X=Br; R=4-CO2CH3 (9a) and HgX2L: X=Br; R=4-CO2CH3 (9b) and X=I; R=4-CO2CH3 (10), were synthesized. All compounds have been structurally characterized by single-crystal X-ray diffraction studies and their spectroscopic (IR, NMR, UV–Vis and fluorescence) properties are described. The structural analyses reveal that compounds 4–9a are centrosymmetric binuclear compounds while compounds 9b (a polymorph of the binuclear compound 9a) and 10 are mononuclear compounds. The HgCl2 compounds are more likely to dimerize via Hg⋯Cl bridges complexed with (E)-N-(pyridin-2-ylmethylidene)arylamine ligands compared with their HgBr2 and HgI2 analogs. This feature of the structural chemistry is correlated with the enhanced Lewis acidity of the mercury in the HgCl2 compounds. Moderating the electronegativity of the substituents in L is shown to influence the strength of the Hg–N(imino) bond in HgCl2L compounds.
We report the synthesis of two N,N‐donor ligands (5 a–b) containing a 2‐chalcogenazoline as the structural motif. These compounds were synthesized from a common intermediate Fischer type aminocarbene ...complex (3). The palladium‐complexes of these N,N‐donor ligands were successfully used as catalytic precursors in the Mizoroki‐Heck coupling reaction between aryl halides and methyl acrylate, styrene and ethylene. For methyl acrylates, high yields with TOF values between 0.6 and 5.5×105 h−1 were obtained. In the case of ethylene, we reached high regioselectivities to obtain a diversity of styrene derivatives under soft pressure conditions, with good values of TON and TOF.
A series of 12 new cadmium compounds, Cd(X
2
)(L) (4, 10), Cd(X
2
)(L)(DMSO) (9), Cd(X
2
)(L)
2
(1-3, 5, 7, 8, 11, and 12), and Cd(Cl
2
)
2
(L)
n
(6) where X = chloride, bromide, and iodide, and ...diimine L = (E)-N-(pyridin-2-ylmethylidene)arylamine, were synthesized and characterized by elemental analyses. The spectroscopic properties were investigated by IR, UV-Vis, fluorescence, and
1
H NMR studies. The solid-state structures of the 12 reaction products were studied by X-ray crystallography. A majority of the structures are binuclear with five-coordinate cadmium centers: dimerization occurs through μ
2
-bridging of the respective halides; the second halide is bound terminally. In the case of X = Br and I, dimerization is circumvented when L carries an additional donor capable of coordinating cadmium (4, 10) or when the additional donor is provided by coordinating solvent (9). A similar situation pertains in the CdCl
2
analog (7). In the case where L strongly coordinates with cadmium, i.e. (6), an edge-shared polymeric chain and octahedrally coordinated cadmium are found as a result of μ
2
-bridging of both chloro ligands. An interesting feature of the crystal packing is the observation of rare C-H
π interactions where the π-system is a chelate ring or a Cd
2
Br
2
unit.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The use of succinamic acid (H
2sucm) in Cu(ClO
4)
2·6H
2O/
N,N′-donor (bpy, phen, dmbpy, 4,4′-bpy) reaction mixture yielded dinuclear complexes and 1D coordination polymers. The coordinative ...versatility of the succinamate(−1) ligand is reflected in the five different ligation modes observed, whereas its hydrogen bonding ability gives rise to interesting 1D, 2D and 3D crystal structures.
The use of succinamic acid (H
2sucm) in Cu(ClO
4)
2·6H
2O/
N,
N′-donor 2,2′-bipyridine (bpy), 1,10-phenanthroline (phen), 4,4′-dimethyl-2,2′-bipyridine (dmbpy), 4,4′-bipyridine (4,4′-bpy) reaction mixtures yielded compounds Cu
2(Hsucm)
3(bpy)
2(ClO
4)·0.5MeOH (
1·0.5MeOH), Cu
2(Hsucm)(OH)(H
2O)(bpy)(ClO
4)
2 (
2), Cu
4(Hsucm)
5(dmbpy)
4
n
(ClO
4)
3
n
·
nH
2O ·0.53
nMeOH (
3·
nH
2O·0.53
nMeOH), Cu
2(Hsucm)
2(dmbpy)
2(H
2O)
2(ClO
4)
2·2H
2O (
4·2H
2O), Cu
2(Hsucm)
2(phen)
2(H
2O)
2(ClO
4)
2·1.8MeOH (
5·1.8MeOH), Cu
2(Hsucm)
2(phen)
2(MeOH)
2(ClO
4)
2·MeOH (
6·MeOH) and Cu(Hsucm)
2(H
2O)(4,4′-bpy)
n
(
7). The succinamate(−1) ligand exists in five different coordination modes in the structures of
1–
7, i.e. the common
syn,
syn μ
2-κ
O:κ
O′ in
1–
6, the μ
2-κ
2
O in
1, the μ
2-κ
2
O:κ
O′ in
1, the μ
3-κ
2
O:κ
2
O′ in
3, and the monodentate κ
O in
7. The primary amide group of Hsucm
− remains uncoordinated and participates in intra- and intermolecular hydrogen bonding interactions leading to interesting crystal structures. Characteristic IR bands of the complexes are discussed in terms of the known structures and the coordination modes of the Hsucm
− ligands. The thermal decomposition of representative complexes was monitored by TG/DTG and DTA measurements.
Reactions of HgX
2
(X = Cl, N
3
, NO
3
) with (E)-2-methoxy-N-(pyridin-2-ylmethylene)aniline (L
1
) and (E)-4-methoxy-N-(pyridin-2-ylmethylene)aniline (L
2
) in ethanol gave two monomers, HgL
1
(Cl)
...2
(1) and HgL
2
(NO
3
)
2
(DMSO) (5), and three coordination polymers, {HgL
1
(N
3
)
2
2
·Hg(N
3
)
2
}
n
(2), HgL
2
(Cl)
2
n
(3), and HgL
2
(NO
3
)
2
n
·nCH
3
CN (4). Compounds 1-5 were characterized by elemental analysis, IR, NMR spectroscopy, and single-crystal X-ray diffraction. The common feature of monomeric 1 and 5 is the presence of intra- and intermolecular Hg-O bonds. In the absence of these, polymeric structures arise as a result of azide, chloride, and nitrate bridging in 2, 3, and 4, respectively. Fluorescent properties of 1-5 were also investigated.
Depending on the formation of Hg-O bonds, monomeric (when present) or polymeric (absent) structures are formed in new Hg(Schiff-base)X
2
(solvent) compounds.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The neutral pentacoordinate silicon(IV) complex 10 (SiON3C skeleton) and the neutral hexacoordinate silicon(IV) complex 11 (SiON4C skeleton) were synthesized, starting from ...methyldi(thiocyanato‐N)silane (7). In addition to their monodentate thiocyanato‐N and methyl ligands, these compounds contain a tridentate dianionic O,N,N ligand (10) or a tridentate monoanionic O,N,N ligand (11). Compounds 10 and 11 were characterized by single‐crystal X‐ray diffraction and solid‐state and solution NMR spectroscopy. According to these studies, compounds 10 and 11 exist in solution as well.
This article describes the preparation and characterization of cis-Ru(bipy)
2
L(ClO
4
)
2
and trans-RuCl
2
L
2
· Cl (bipy = 2,2′-bipyridyl and L = ortho-phenylenediamine (o-phd), 2-aminopyridine ...(2-apy) and 2-aminobenzonitrile (2-abn), and examines the catalytic oxidations of benzyl alcohol, benzohydrol and pipronyl alcohol by cis-Ru(bipy)
2
(o-phd)(ClO
4
)
2
and trans-RuCl
2
(o-phd)
2
· Cl complexes at room temperature and in the presence of N-methyl morpholine-N-oxide (NMO) as co-oxidant.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
A systematic investigation of the reactions of 3d-metal ions with succinamate(−1) (LH
−) in the presence of aromatic
N,
N
′-donors has been initiated and initial results are described. Several ...reaction schemes involving various copper(II) sources, LH
− and 4,4
′-dimethyl-2,2
′-bipyridine (dmbpy) or 2,2
′-bipyridine (bpy) afforded the new complexes Cu
2(LH)
3(dmbpy)
2(OH)
·
H
2O
·
MeOH (
1a), Cu
2(LH)
2(dmbpy)
2(H
2O)
2(ClO
4)
2
·
2H
2O (
2), Cu
4(LH)
5(dmbpy)
4
n
(ClO
4)
3
n
·
nH
2O
·
0.53
nMeOH (
3) and Cu
2(OH)(H
2O)(LH)(bpy)
2(ClO
4)
2 (
4), which have been characterized by single-crystal X-ray crystallography and IR spectroscopy. The dinuclear complexes contain extremely rare cores, while the novel cationic coordination polymer
3 consists of alternating dinuclear units.
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