Fluorinated alcohols and their metal complexes

Willis, Christopher J.

doi:10.1016/0010-8545(88)80003-1

Cited by 65 publications

(30 citation statements)

References 252 publications

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“…The Onsager plots [22] for complexes 1, 4 and 7 are shown in Figure 4; those for 2 and 5 are in Figure S7 in the Supporting Information, and those for 3 and 6 in Figure S8 along with the control 1:1 electrolyte and non-electrolyte measurements. The solvent THF was hypothesized to disrupt any K···F/O interactions due to the weak basicity of the fluorinated alkoxides (pK a (HOC 4 F 9 ) = 5.4 and pK a (HOCMeMe F 2 ) = 9.6), [23] and therefore, yield 1:1 electrolytes, regardless of the encapsulation of K + . [20,21] and d KÀF/O are the crystallographically determined K···F or KÀO distances.…”

Section: Bond Valence Analysis: Bond Valencementioning

confidence: 99%

K⋅⋅⋅F/O Interactions Bridge Copper(I) Fluorinated Alkoxide Complexes and Facilitate Dioxygen Activation

Lum

Tahsini

Golen

et al. 2013

Chemistry A European J

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Seven E[Cu(OR)2] copper(I) complexes (E = K(+), {K(18C6)}(+) (18C6 = [18]crown-6), or Ph4P(+); R = C4F9, CPhMe(F)2, and CMeMe(F)2) have been prepared and their reactivity with O2 studied. The K[Cu(OR)2] species react with O2 in a copper-concentration-dependent manner such that 2:1 and 3:1 Cu/O2 adducts are observed manometrically at -78 °C. Analogous reactivity with O2 is not observed with the {K(18C6)}(+) or Ph4P(+) derivatives. Solution conductivity data demonstrate that these K[Cu(OR)2] complexes do not behave as 1:1 electrolytes in solution. The K(+) ions induce aggregation of multiple [Cu(OR)2](-) units through K⋅⋅⋅F/O interactions and thereby effect irreversible O2 reduction by multiple Cu centers. Bond valence analyses for the potassium cations confirm the dominance of the fluorine interactions in the coordination spheres of K(+) ions. Intramolecular hydroxylation of ligand aryl and alkyl C-H bonds is observed. Nucleophilic reactivity with CO2 is observed for the oxygenated Cu complexes and a Cu(II) carbonate has been isolated and characterized.

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Section: Bond Valence Analysis: Bond Valencementioning

confidence: 99%

K⋅⋅⋅F/O Interactions Bridge Copper(I) Fluorinated Alkoxide Complexes and Facilitate Dioxygen Activation

Lum

Tahsini

Golen

et al. 2013

Chemistry A European J

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“…66 The 3 equivalent reaction produces a Y᎐N-(SiHMe 2 ) 2 fragment with a very low-energy Si᎐H stretch vibration of 1888 cm Ϫ1 . Extended Y ؒ ؒ ؒ (Si᎐H) interaction in this reaction product is also indicated by a 1 H NMR resonance at .…”

Section: Reactions Of [Y{n(sihme 2 ) 2 } 3 (Thf) 2 ] With Alme 3 : Thmentioning

confidence: 99%

“…48c, 65 However, the Si᎐H stretch vibration at 2151 cm Ϫ1 associated with the non-metal bonded SiHMe 2 moiety cannot be 'removed' by extracting the hybrid material 9a with HOC(CF 3 ) 3 -thf solutions (pK a = 5.7). 66 In the presence of the amidation product 'O 3 SiN(SiHMe 2 ) 2 ', the hydrolytically unstable Si᎐N bonds should be cleaved completely by the acidic alcohol. As expected, the yttrium surface species of 9a can be 'degrafted' as perfluorinated alkoxide complexes 66 to render support materials (0.8 wt.% Y) displaying nitrogen adsorptiondesorption isotherms similar to those of 10a.…”

Section: Grafting Of [Y{n(sihme 2 ) 2 } 3 (Thf) 2 ] 1a Onto Mesoporou...mentioning

confidence: 99%

Synthesis and structural characterisation of rare-earth bis(dimethylsilyl)amides and their surface organometallic chemistry on mesoporous MCM-41 †

Anwander

Runte

Eppinger

et al. 1998

J. Chem. Soc., Dalton Trans.

261

227

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Rare-earth silylamides of type [Ln{N(SiHMe 2 ) 2 } 3 (thf) x ] (Ln = Sc, Y, La, Nd, Er or Lu) have been prepared in high yield by reaction of 2.9 equivalents of Li[N(SiHMe 2 ) 2 ] with [LnCl 3 (thf) x ] in n-hexane or thf, depending on the solubility of the rare-earth halide precursor. The complexes [Ln{N(SiHMe 2 ) 2 } 3 (thf) 2 ] (Ln = Y, La to Lu) are isostructural in the solid state, adopting the preferred (3 ϩ 2, distorted) trigonal bipyramidal geometry, whilst [Sc{N(SiHMe 2 ) 2 } 3 (thf)] has a distorted tetrahedral co-ordination geometry and short Sc ؒ ؒ ؒ Si contacts in the solid state. The reaction of [Y{N(SiHMe 2 ) 2 } 3 (thf) 2 ] with varying amounts of AlMe 3 resulted in desolvation and alkylation with formation of AlMe 3 (thf), {AlMe 2 [µ-N(SiHMe 2 ] 2 } 2 and heterobimetallic (Y/Al) species. The generation of surface-bonded '(᎐ ᎐ ᎐ SiO) x Y[N(SiHMe 2 ) 2 ] y ' and '᎐ ᎐ ᎐ SiOSiHMe 2 ' moieties via the grafting of [Y{N(SiHMe 2 ) 2 } 3 (thf) 2 ] onto the mesoporous silicate MCM-41 is described in detail. Consideration is given to the factors governing the siloxide formation and silylation reactions, and the thermal stability of the surface species.Rare-earth amides, and in particular silylamides, 1 are of potential relevance in catalysis 2 and the material sciences. 3 Furthermore, the synthetic versatility of the Ln᎐N(SiMe 3 ) 2 moiety is well established in amine elimination reactions known as the silylamide route (Scheme 1). 1,4 Rare-earth amides are also capable of alkylation reactions via Lewis acid-base derived heterobimetallic species. 5,6 Advantages of the Ln᎐N(SiMe 3 ) 2 -based silylamide route are (i) facile availability of mono-and heterobi-metallic amide precursors, (ii) favourable (mild) reaction conditions including non-co-ordinating solvents, ambient temperature, smooth work-up procedures and 'quantitative' yield, (iii) avoidance of halide contamination and (iv) donor ligand-free products due to the weak donor capability of the released silylamine. 1 Complexes [Ln{N(SiHMe 2 ) 2 } 3 (thf) 2 ] derived from the sterically less bulky bis(dimethylsilyl)-amide ligand were introduced better to cope with the steric requirements of catalytically relevant, bulky and chelating ancillary ligands such as salen or linked cyclopentadienyl derivatives. 7 We report here a detailed synthetic and structural examination of these versatile synthetic building blocks. In addition, AlMe 3 -directed desolvation and alkylation reactions are discussed.Very recently, we found that many features of the homogeneously performed silylamide route can be transferred to a heterogeneous medium (Scheme 1). 8 Such a supramolecular approach allowed the grafting of rare-earth silylamide complexes onto a mesoporous aluminosilicate of type MCM-41 9,10 via surface organometallic chemistry. 11 The presence of 'Si᎐H' as a spectroscopic probe helped to unravel the chemical anchoring of the silylamides which proceeds via siloxide formation and silylation reactions. In this work more light will be shed on the surface organometallic chem...

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“…[23] Magnetic susceptibility and elemental analysis data were reported for K 2 [M(ddfp) 2 ], (M = Mn, Ni, Cu) for which square-planar geometry was proposed.…”

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confidence: 99%

High‐Spin Square‐Planar Co^II and Fe^II Complexes and Reasons for Their Electronic Structure

et al. 2011

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More than half a century of intense investigation in coordination compounds has laid a firm foundation for our understanding of the ligand fields in transition-metal complexes. [1] Complexes of the heavier 4d and 5d metals are generally low spin, whereas the spin of 3d metal complexes can be high or low, depending on ligand characteristics. The number and type of donor atoms, ligand substituents, and the presence or absence of chelate rings all influence metal spin states. A combination of data-mining and detailed computational study have quantified recently these empirical observations. [2,3] In spite of such variety, there are still some types of metal complexes that are rarely observed.The stereospinomers [3] of high-spin, square-planar complexes, for example, are extremely rare because the large separation of the d [7] is known whose high-spin examples are subtly dependent on ligand substitution. Until the structure was confirmed [8] as tetrameric with octahedral coordination at the Co center, [Co(acac) 2 ] was postulated to have square-planar geometry based on magnetic and spectroscopic data that differed from tetrahedral complexes.[9] A search of the Cambridge Structural Database (V 5.32) [10] [22] Ni. [20] Spectroscopic [20] and computational [18] work have shown that these fluorinated ligands are medium field ligands, on par with OH À and F À , and stronger than NCO À . The electron-withdrawing power of extensively fluorinated ligands reduces the p-donor character of the O atom, such that bridging is not observed and mononuclear species are readily prepared.More recently, we have begun studies of the chelating perfluoropinacolate ligand, ddfp 2À . [23] Magnetic susceptibility and elemental analysis data were reported for K 2 [M(ddfp) 2 ], (M = Mn, Ni, Cu) for which square-planar geometry was proposed.[24] An octahedral bis-H 2 O adduct, (Me 4 N) 2 [Co-(OH 2 ) 2 (ddfp) 2 ] has been proposed based on elemental analysis data. [25] Despite the relative ease in making the [M(ddfp) 2 ] 2À complexes with first-row transition metals, no examples of M = Co II or Fe II have been published. We now report a highspin, square-planar Co II complex, {K(DME) 2 } 2 [Co(ddfp) 2 ] (1), and the analogous high-spin, square-planar Fe II complex {K(DME) 2 } 2 [Fe(ddfp) 2 ] (2). We also provide a discussion of three other square-planar {MO 4 } species from the recent literature whose composition and spin-state characteristics clarify the ligand requirements for the highly unusual highspin, square-planar combination in late row 3d metals.Compound 1 has been prepared as pale pink crystals as shown in Equation (1), and is stable in an inert atmosphere and in various organic solvents, but yields a brown oil upon prolonged exposure to air. Iron-containing 2, and the Zn II derivative, {K(DME) 2 } 2 [Zn(ddfp) 2 ] (3), were similarly prepared as purple-pink, and colorless crystals, respectively. No

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Fluorinated alcohols and their metal complexes

Cited by 65 publications

References 252 publications

K⋅⋅⋅F/O Interactions Bridge Copper(I) Fluorinated Alkoxide Complexes and Facilitate Dioxygen Activation

K⋅⋅⋅F/O Interactions Bridge Copper(I) Fluorinated Alkoxide Complexes and Facilitate Dioxygen Activation

Synthesis and structural characterisation of rare-earth bis(dimethylsilyl)amides and their surface organometallic chemistry on mesoporous MCM-41 †

High‐Spin Square‐Planar Co^II and Fe^II Complexes and Reasons for Their Electronic Structure

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Fluorinated alcohols and their metal complexes

Cited by 65 publications

References 252 publications

K⋅⋅⋅F/O Interactions Bridge Copper(I) Fluorinated Alkoxide Complexes and Facilitate Dioxygen Activation

K⋅⋅⋅F/O Interactions Bridge Copper(I) Fluorinated Alkoxide Complexes and Facilitate Dioxygen Activation

Synthesis and structural characterisation of rare-earth bis(dimethylsilyl)amides and their surface organometallic chemistry on mesoporous MCM-41 †

High‐Spin Square‐Planar CoII and FeII Complexes and Reasons for Their Electronic Structure

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High‐Spin Square‐Planar Co^II and Fe^II Complexes and Reasons for Their Electronic Structure