Title: Exploring opportunities for tuning phenyltris(pyrazol-1-yl)borate donation by varying the extent of phenyl substituent fluorination
The importance of electron deficient Tp ligands motivates the introduction of electron-withdrawing substituents into the scorpionate framework. Since perfluorophenyltris(pyrazol-1-yl)borate affects significant anodic shifts in half-cell potentials in their metal complexes relative those of phenyltris(pyrazol-1-yl)borate analogues, the tuning opportunities achieved using 3,4,5-trifluorophenyl- and 3,5-bis(trifluoromethyl)phenyl(pyrazol-1-yl)borates were explored. Bis(amino)boranes ((3,4,5-F)C 6 H 2 )B(NMe 2 ) 2 and ((3,5-CF 3 )C 6 H 3 )B(NMe 2 ) 2 are precursors to fluorinated tris(pyrazol-1-yl)phenylborates. Thallium salts of these scorpionates exhibit bridging asymmetric κ 3 - N , N , N coordination modes consistent with the reduced π-basicity of the fluorinated phenyl substituents relative those of other structurally characterized tris(pyrazol-1-yl)phenylborates. While a comparative analysis of the spectral and X-ray crystallographic data for classical Mo(0), Mo( ii ), Mn( i ), Fe( ii ) and Cu( ii ) complexes of [((3,4,5-F)C 6 H 2 )Bpz 3 ] − and [((3,5-CF 3 )C 6 H 3 )Bpz 3 ] − could not differentiate these ligands with respect to their metal-based electronic impacts, cyclic voltammetry suggests that 3,4,5-trifluorophenyl- and 3,5-bis(trifluoromethyl)phenyl(pyrazol-1-yl)borates affect similar anodic shifts within their metal complexes, with coordination of [((3,5-CF 3 )C 6 H 3 )Bpz 3 ] − rendering metal centers more difficult to oxidize, and sometimes even more difficult to oxidize than their [C 6 F 5 Bpz 3 ] − analogues. These data suggest that the extent of phenyl substituent fluorination necessary to minimize metal center electron-richness in phenyltris(pyrazol-1-yl)borate complexes cannot be confidently predicted. more »« less
Lapsheva, Ekaterina N.; Cheisson, Thibault; Álvarez Lamsfus, Carlos; Carroll, Patrick J.; Gau, Michael R.; Maron, Laurent; Schelter, Eric J.
(, Chemical Communications)
null
(Ed.)
The reactivity of alkali metal capped Ce( iv ) imido compounds [M(DME) 2 ][CeNAr F (TriNOx)] ( 1-M with M = K, Rb, Cs and Ar F = 3,5-bis(trifluoromethyl)phenyl) with CO 2 and organic isocyanates has been evaluated. 1-Cs reacted with CO 2 to yield an organocarbamate complex. Reaction of 1-K and 1-Rb with organic isocyanates yielded organoureate Ce( iv ) complexes.
Lakhi, Jaspreet S.; Patterson, Monika R.; Dias, H. V.
(, New Journal of Chemistry)
null
(Ed.)
Copper( i ) and silver( i ) pyrazolate complexes {[3,5-(3,5-(CF 3 ) 2 Ph) 2 Pz]Cu} 3 and {[3,5-(3,5-(CF 3 ) 2 Ph) 2 Pz]Ag} 3 have been synthesized using the fluorinated 3,5-(diaryl)pyrazole 3,5-(3,5-(CF 3 ) 2 Ph) 2 PzH and copper( i ) oxide and silver( i ) oxide, respectively. The gold( i ) analog was obtained from a reaction between Au(THT)Cl and [3,5-(3,5-(CF 3 ) 2 Ph) 2 Pz]H/NaH. The X-ray crystal structures show that the coinage metal complexes {[3,5-(3,5-(CF 3 ) 2 Ph) 2 Pz]M} 3 (M = Cu, Ag, Au) are trinuclear in the solid state. They feature distorted nine-membered M 3 N 6 metallacyclic cores. The M–N distances follow Cu < Au < Ag, which is the trend expected from covalent radii of the corresponding coinage metal ions. The 3,5-(3,5-(CF 3 ) 2 Ph) 2 PzH forms hydrogen bonded trimers in the solid state that are further organized by π-stacking between aryl rings. Solid samples of {[3,5-(3,5-(CF 3 ) 2 Ph) 2 Pz]M} 3 display blue photoluminescence. The copper complex {[3,5-(3,5-(CF 3 ) 2 Ph) 2 Pz]Cu} 3 is an excellent catalyst for mediating azide–alkyne cycloaddition chemistry.
Pellei, Maura; Del_Gobbo, Jo’; Caviglia, Miriam; Gandin, Valentina; Marzano, Cristina; Karade, Deepika V; Noonikara_Poyil, Anurag; Dias, H_V Rasika; Santini, Carlo
(, International Journal of Molecular Sciences)
The 3d transition metal (Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II)) complexes, supported by anions of sterically demanding β-diketones, 1,3-dimesitylpropane-1,3-dione (HLMes) and 1,3-bis(3,5-bis(trifluoromethyl)phenyl)-3-hydroxyprop-2-en-1-one (HLCF3), were synthesized and evaluated for their antitumor activity. To assess the biological effects of substituents on phenyl moieties, we also synthesized and investigated the analogous metal(II) complexes of the anion of the less bulky 1,3-diphenylpropane-1,3-dione (HLPh) ligand. The compounds [Cu(LCF3)2], [Cu(LMes)2] and ([Zn(LMes)2]) were characterized by X-ray crystallography. The [Cu(LCF3)2] crystallizes with an apical molecule of solvent (THF) and features a rare square pyramidal geometry at the Cu(II) center. The copper(II) and zinc(II) complexes of diketonate ligands, derived from the deprotonated 1,3-dimesitylpropane-1,3-dione (HLMes), adopt a square planar or a tetrahedral geometry at the metal, respectively. We evaluated the antitumor properties of the newly synthesized (Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II)) complexes against a series of human tumor cell lines derived from different solid tumors. Except for iron derivatives, cellular studies revealed noteworthy antitumor properties, even towards cancer cells endowed with poor sensitivity to the reference drug cisplatin.
Elashkar, Ahmed H.; Parasar, Devaborniny; Muñoz‐Castro, Alvaro; Doherty, Cara M.; Cowan, Matthew G.; Dias, H. V. Rasika
(, ChemPlusChem)
Abstract Non‐porous small molecule adsorbents such as {[3,5‐(CF3)2Pz]Cu}3(where Pz=pyrazolate) are an emerging class of materials that display attractive features for ethene−ethane separation. This work examines the chemistry of fluorinated copper(I) pyrazolates {[3,5‐(CF3)2Pz]Cu}3and {[4‐Br‐3,5‐(CF3)2Pz]Cu}3with much larger 1‐butene in both solution and solid state, and reports the isolation of rare 1‐butene complexes of copper(I), {[3,5‐(CF3)2Pz]Cu(H2C=CHC2H5)}2and {[4‐Br‐3,5‐(CF3)2Pz]Cu(H2C=CHC2H5)}2and their structural, spectroscopic, and computational data. The copper−butene adduct formation in solution involves olefin‐induced structural transformation of trinuclear copper(I) pyrazolates to dinuclear mixed‐ligand systems. Remarkably, larger 1‐butene is able to penetrate the dense solid material and to coordinate with copper(I) ions at high molar occupancy. A comparison to analogous ethene and propene complexes of copper(I) is also provided.
Alexandropoulos, Dimitris I.; Vignesh, Kuduva R.; Xie, Haomiao; Dunbar, Kim R.
(, Dalton Transactions)
Two new homoleptic Dy III compounds [Dy(Tp Me2 ) 2 ][DyCl 3 (Tp Me2 )]·CH 2 Cl 2 ( 1 ) and [Dy(Tp Me2 ) 2 ]I ( 3 ) as well as a heteroleptic (NMe 4 )[DyCl 3 (Tp Me2 )] ( 2 ) (Tp Me2 = tris(3,5-dimethylpyrazolyl)borate) species are reported. Magnetic studies revealed that 1 is a single-molecule magnet (SMM) with an energy barrier of U eff = 80.7 K with τ 0 = 6.2 × 10 −7 s under a zero applied field. Compound 3 exhibits a U eff of 13.5 K with τ 0 = 1.6 × 10 −6 s under a 0.08 T applied field. Ab initio CASSCF + RASSI-SO calculations were performed to further investigate the magnetic behavior of complexes 1–3 . The results support experimental magnetic data for 1 and 3 and indicate that an intermolecular dipolar interaction of ( zJ = −0.1 cm −1 ) is responsible for the SMM behavior of 1 .
Fischer, Paul J., Roe, Charley B., Stephenson, Jasmine N., Dunscomb, Rachel J., Carthy, Camille L., Nataro, Chip, and Young, Victor G. Exploring opportunities for tuning phenyltris(pyrazol-1-yl)borate donation by varying the extent of phenyl substituent fluorination. Retrieved from https://par.nsf.gov/biblio/10447559. Dalton Transactions 52.17 Web. doi:10.1039/d3dt00735a.
Fischer, Paul J., Roe, Charley B., Stephenson, Jasmine N., Dunscomb, Rachel J., Carthy, Camille L., Nataro, Chip, and Young, Victor G.
"Exploring opportunities for tuning phenyltris(pyrazol-1-yl)borate donation by varying the extent of phenyl substituent fluorination". Dalton Transactions 52 (17). Country unknown/Code not available. https://doi.org/10.1039/d3dt00735a.https://par.nsf.gov/biblio/10447559.
@article{osti_10447559,
place = {Country unknown/Code not available},
title = {Exploring opportunities for tuning phenyltris(pyrazol-1-yl)borate donation by varying the extent of phenyl substituent fluorination},
url = {https://par.nsf.gov/biblio/10447559},
DOI = {10.1039/d3dt00735a},
abstractNote = {The importance of electron deficient Tp ligands motivates the introduction of electron-withdrawing substituents into the scorpionate framework. Since perfluorophenyltris(pyrazol-1-yl)borate affects significant anodic shifts in half-cell potentials in their metal complexes relative those of phenyltris(pyrazol-1-yl)borate analogues, the tuning opportunities achieved using 3,4,5-trifluorophenyl- and 3,5-bis(trifluoromethyl)phenyl(pyrazol-1-yl)borates were explored. Bis(amino)boranes ((3,4,5-F)C 6 H 2 )B(NMe 2 ) 2 and ((3,5-CF 3 )C 6 H 3 )B(NMe 2 ) 2 are precursors to fluorinated tris(pyrazol-1-yl)phenylborates. Thallium salts of these scorpionates exhibit bridging asymmetric κ 3 - N , N , N coordination modes consistent with the reduced π-basicity of the fluorinated phenyl substituents relative those of other structurally characterized tris(pyrazol-1-yl)phenylborates. While a comparative analysis of the spectral and X-ray crystallographic data for classical Mo(0), Mo( ii ), Mn( i ), Fe( ii ) and Cu( ii ) complexes of [((3,4,5-F)C 6 H 2 )Bpz 3 ] − and [((3,5-CF 3 )C 6 H 3 )Bpz 3 ] − could not differentiate these ligands with respect to their metal-based electronic impacts, cyclic voltammetry suggests that 3,4,5-trifluorophenyl- and 3,5-bis(trifluoromethyl)phenyl(pyrazol-1-yl)borates affect similar anodic shifts within their metal complexes, with coordination of [((3,5-CF 3 )C 6 H 3 )Bpz 3 ] − rendering metal centers more difficult to oxidize, and sometimes even more difficult to oxidize than their [C 6 F 5 Bpz 3 ] − analogues. These data suggest that the extent of phenyl substituent fluorination necessary to minimize metal center electron-richness in phenyltris(pyrazol-1-yl)borate complexes cannot be confidently predicted.},
journal = {Dalton Transactions},
volume = {52},
number = {17},
author = {Fischer, Paul J. and Roe, Charley B. and Stephenson, Jasmine N. and Dunscomb, Rachel J. and Carthy, Camille L. and Nataro, Chip and Young, Victor G.},
}
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