In the alkyne cyclotrimerization reactions catalyzed by the rhodium(I) complexes of new heteroscorpionate ligands composed of pyrrole and pyridine, electron donating counter anions placed near the ...metal center considerably enhanced the reactivity through anion recognition with the pyrrolic NH moiety.
New heteroscorpionate ligands (
1 and
2) having a di(pyridin-2-yl)(1
H-pyrrol-2-yl)methane substructure are synthesized. X-ray crystallographic analysis on
1 and
2 reveals that they form unique hydrogen bonding networks depending on the size of neighboring groups in solid states.
1 and
2 can form cationic rhodium(I) complexes, wherein the counter anions form hydrogen bondings with the pyrrolic NH moiety. In alkyne cyclotrimerization reactions using those complexes as catalyst, the catalytic activity is significantly enhanced when electron-donating counter anions is placed near the metal center.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The synthesis and characterization of the ditopic bis(pyrazol‐1‐yl)borate ligand Li2p‐C6H4(B(C6F5)pz2)2 is reported (pz = pyrazol‐1‐yl). Compared to the corresponding t‐butyl derivative ...Li2p‐C6H4(B(t‐Bu)pz2)2, the C6F5‐substituted scorpionate is significantly more stable towards hydrolysis. Reaction of Li2p‐C6H4(B(C6F5)pz2)2 with two equivalents of MnCl2 leads to the formation of coordination polymers {(MnCl2)2(Li(THF)3)2p‐C6H4(B(C6F5)pz2)2}∞ featuring penta‐coordinate MnII ions chelated by one bis(pyrazol‐1‐yl)borate fragment and further bonded to three chloride ions. Two of the three chloride ions are also coordinated to a neighbouring MnII ion; the third chloro ligand is shared between the MnII centre and a Li(THF)3 moiety.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The synthesis and full characterization of the sterically demanding ditopic lithium bis(pyrazol‐1‐yl)borates Li2p‐C6H4(B(Ph)pzR2)2 is reported (pzR = 3‐phenylpyrazol‐1‐yl (3Ph), 3‐t‐butylpyrazol‐1‐yl ...(3tBu)). Compound 3Ph crystallizes from THF as THF‐adduct 3Ph(THF)4 which features a straight conformation with a long Li···Li distance of 12.68(1) Å. Compound 3tBu was found to function as efficient and selective scavenger of chloride ions. In the presence of LiCl it forms anionic complexes 3tBuCl− with a central Li‐Cl‐Li core (Li···Li = 3.75(1) Å).
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
We report the optimized syntheses and the solid state structures of the alkali metal tris(pyrazol‐1‐yl)borates MMe2NBpz3 (M = Na+ (1), K+ (2); pz = pyrazol‐1‐yl) and KPhBpz3 (3). Even though 1 and 2 ...consist of polymeric chains in the solid state, it is possible to identify subunits where the Me2NBpz3− ion acts as tridentate ligand towards Na+ and K+ and binds via two of its pyrazolyl rings and its dimethylamino nitrogen atom (κ3Npz,Npz,NNMe). In 3, the ligand PhBpz3− employs two pyrazolyl donors and the π‐face of its phenyl substituent for potassium coordination (κ3N,N,C).
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Fluorenyl/tris(pyrazol-1-yl)borate hybrid ligands have been prepared, which are of potential use for the generation of dinuclear aggregates as well as mononuclear constrained-geometry complexes.
Two ...fluorenyl/tris(pyrazol-1-yl)borate hybrid ligands, FlBpz
3Li and FlB(pz
3-
tBu
)
3Li, have been synthesized and structurally characterized by X-ray crystallography (Fl: 9-fluorenyl; pz: pyrazolyl). From the reaction of FlBpz
3Li and ZnCl
2 in THF, the dinuclear complex (THF)
3Lipz(Fl)Bpz
2ZnCl
2 was obtained in which a ZnCl
2 moiety is chelated by two pyrazolyl ligands while the third pz ring coordinates to an Li(THF)
3 fragment. Acetonitrile solutions of the compound gradually transform into the mononuclear species Fl(pz)Bpz
2Znpz
2B(pz)Fl featuring a distorted tetrahedral ZnN
4 core. In all molecular structures of FlBpz
3
− or FlB(pz
3-
tBu
)
3
− complexes investigated so far, the hybrid ligands adopt very similar conformations with only two pyrazolyl rings bonded to the central metal, whereas the third pyrazolyl acts as dangling substituent. The fluorenyl substituent of FlBpz
3Li may be deprotonated with KH in quantitative yield.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In the title complex, Cu(C
27
H
40
BN
6
S
3
)(C
18
H
15
P)·2CHCl
3
, the Cu
I
atom is surrounded in a trigonal-planar arrangement by the triphenylphosphane ligand and two of the three S atoms of the ...scorpionate ligand with an additional 3-center–2-electron B—H...Cu interaction, with the H atom as the apex of a pyramid B—H = 1.140 (17) Å and Cu—H = 1.826 (16) Å.
The X-ray crystal structure of (C
54
H
42
B
2
N
12
Zn)*2(C H Cl
3
) is reported. The title compound is a chloroform-solvated neutral complex crystallizing in the Triclinic space group, P − 1, with ...two half complexes (each located on a crystallographic center of inversion) and two full chloroform molecules appearing in the asymmetric unit. The capping ligands are related by symmetry and together form, essentially, an octahedral coordination sphere. Strain is apparent in the complex as indicated by asymmetric bond distances and angles. Final statistical data:
R
= 4.60% with
I
> 2σ(
I
),
a
= 11.2912(8) Å,
b
= 14.7912(11) Å,
c
= 17.0047(13) Å, α = 72.3560(10)°, β = 89.8950(10)°, γ = 88.1010(10)°,
Z
= 2.
Graphical Abstract
Crystal structure of a Zn complex containing two scorpionate ligands is reported.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Cette thèse porte sur la synthèse et la caractérisation de complexes octaédrique de fer(II) et fer(III) coordinés par un ligand tridente de type scorpionate (symétrie fac) et par trois ligands ...cyanures. Leur utilisation en tant que metalloligand face à des ions métalliques partiellement bloqués est étudiée. Les ligands cyanures, de par leur caractère ambidente, permettent un accès facile aux espèces hétérobimétalliques. De plus, ces ligands sont connus pour transmettre efficacement l'interaction d'échange magnétique et donc pour favoriser la communication électronique intramoléculaire entre les ions métalliques qu'ils relient. La fonctionalisation des ligands scorpionates permet de contrôler les propriétés électroniques intrinsèques des complexes précurseurs de fer, et donc de moduler les propriétés des espèces polynucléaires obtenues à partir de ces dernières par auto-assemblage. Dans cette thèse, un intérêt particulier est porté aux systèmes {FeCo} en raison de leur capacité à présenter une bistabilité électronique (propriétés photomagnétiques ou de molécules/chaines aimants). Les systèmes cyanuré {FeCo} sont particulièrement adaptés pour l'observation de réarrangements électroniques thermo- et/ou photo-induit, comme en témoignent le nombre important de composés cyanurés photomagnétiques dans la littérature.
The work presented in this PhD dissertation focuses on the synthesis and the characterisation of octahedral iron(II) and iron(III) complexes coordinated by a tridentate ligand of the scorpionate family (fac- geometry) and three cyanide ligands. Their use as metalloligands in respect to partially blocked metal ions is studied. Because of their ambidentate character, cyanide ligands open the door to facile synthesis of heterobimetallic species. Moreover, these ligands are known to be efficient magnetic exchange interaction transmitter, thus favouring intramolecular electronic communication between the metal ions they are bridging. The functionalisation of scorpionate ligands allows control over the intrinsic electronic properties of the iron precursor complexes, thus allows to tune the properties of the obtained polynuclear species from the latter by self-assembly. In this PhD dissertation, a particular interest was taken in {FeCo} systems because of their potential ability to exhibit electronic bistability (photomagnetic properties or SMM/SCM behaviour). Cyanide-bridged {FeCo} systems are particularly suitable for the observation of thermally or light-induced electron rearrangements, as testified by the wide range of photomagnetic cyanide-bridged compounds in the literature.
The title compound crystallizes in the monoclinic space group P21/n with a = 8.706(1), b = 9.192(1), c = 15.261(2) Å, β = 94.740(3)°, V = 1217.0(3) Å3, Z = 4, Dcalc = 2.278 g cm–3. The ...tris(imidazolyl)borate ligand bridges between three thallium atoms. The structure consists of one‐dimensional twisted ladder‐like strands.
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