Publications by authors named "Ilia Korobkov"

Treatment of (PDI)Fe(N) (PDI, 2,6-(2,6-iPrCHN═CMe)CHN) with CO and ethylene resulted in the formation of a homologous series of saturated and unsaturated iron carboxylate products, (PDI)Fe(OCR), the distribution of which depends on the ratio of the reagents. The solid-state and electronic structures of a saturated product, (PDI)Fe(OCCH), were elucidated. Product distributions, deuterium labeling studies, and stoichiometric experiments support initial formation of a five-membered metallalactone intermediate, which undergoes subsequent ethylene insertions to generate macrocyclic metallalactones.

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A recently designed nitrogen-rich ligand is successfully applied as a scaffold for lanthanide ions to show that the intricate chemistry of energetic materials can be combined with other fields of research, including that of molecular magnetism. Herein, we report the synthesis of two different types of molecular architectures using a single ligand template, in which the discrete monomer exhibits single-molecule magnet-like behaviour along with two well-isolated modes of magnetic relaxation.

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We report an easily prepared bis(thioether) amine ligand, SNS, along with the synthesis, characterization, and reactivity of the paramagnetic iron(II) bis(amido) complex, [Fe(κ-SNS)] (1). Binding of the two different thioethers to Fe generates both five- and six-membered rings with Fe-S bonds in the five-membered rings (av 2.54 Å) being significantly shorter than those in the six-membered rings (av 2.

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Efficient electrocatalytic production of H from mixed water/acetonitrile solutions was achieved using three new Co complexes supported by the neutral pincer ligand bis(diphenylphosphino)-2,6-di(methylamino)pyridine ("PN P"). At -1.9 V vs.

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The reactivity of carbon dioxide with vanadium(III) aryloxo complexes has been investigated. The formation of either carbon monoxide or incorporation into the ligand system with the ultimate formation of organic ester was observed depending on the overall electron donor ability of the ligand field. DFT calculations were carried out to investigate the proposed mechanism for carbon dioxide coordination and reduction.

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A planar tetradentate 3,6-bis(2-pyrimidyl)-1,2,4,5-tetrazine (BpymTz) templating chelate affords the formation of an unprecedented BpymTz˙ radical anion bridged {Ni} complex. Detailed magnetic measurements performed on the isolated air stable [Ni(BpymTz˙)Cl(DMF)]Cl·0.5(HO) compound reveal strong ferromagnetic Ni-BpymTz˙ interactions with a coupling constant of J = 98.

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Binding sites are at the heart of all host-guest systems, whether biological or chemical. When considering binding sites that form covalent bonds with the guest, we generally envision a single, highly specific binding motif. Through single-crystal X-ray crystallography, the dynamic binding of a guest that displays a variety of covalent binding motifs in a single site of adsorption is directly observed for the first time.

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The pivotal role of ππ interactions in the inclusion behaviour of a series of organometallic sandwich compounds is studied through single-crystal X-ray diffraction. The confinement effects of a crystalline sponge host are investigated where, notably, we observe an enhanced rotation of the ligand ring once encapsulated by the nanoporous framework, as evidenced by SSNMR experiments.

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A Mn(i) tris(2-pyridylmethyl)amine complex fac-[Mn(κ-tpa) (CO)]OTf carries out electrocatalytic hydrogen evolution from neutral water in acetonitrile. Bulk electrocatalytic studies showed that the catalyst functions with a moderate Faradaic efficiency and turn over frequency. DFT computations support the role of the tpa ligand as a shuttle to transfer of protons to the metal center.

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The preparation of η-cyclopentadienyl (η-CR), η-arene (η-CR), and η-cyclooctatetraenyl (η-CR) bridging motifs are common in organometallic chemistry; however, the synthetic preparation of η-cycloheptatrienyl (η-CR) bridging motifs has remained a synthetic challenge in 4f chemistry. To this end, we have developed a synthetic route towards a series of rare dinuclear organolanthanide inverse sandwich complexes containing the elusive η-CH bridge. Herein, we present the structures and magnetic properties of the lanthanide inverse sandwich complexes [KLn(CH)(N(SiMe))] (Ln = Gd (), Dy (), Er ()) and [K(THF)Er(CH)(N(SiMe))] ().

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Treatment of Ni(0) complexes 1a-e with sub-atmospheric pressures of trifluoroethylene (TrFE) affords hydrofluoronickelacyclopentanes LNi(CFH) 2a-e (L = PPh, P(O-o-tol), PPhMe, PPhMe, PMe). Fluorine NMR analysis of 2a-e demonstrates predominant formation of three (of the possible six) isomers upon oxidative cycloaddition of TrFE: the cis and trans head-tail isomers and the trans head-head isomer, where the CHF group is defined as the TrFE "head". The respective ratios of LNi(CFH) isomers are influenced by the nature of L, with smaller phosphines favoring the thermodynamically preferred (from DFT calculations) trans head-head isomer (cf.

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The preparation and characterization of a series of divalent 3d transition metal complexes supported by a tridentate planar bis(iminopyridine) ligand are reported. The complexes {2,6-[PhC[double bond, length as m-dash]N(tBu2C6H3)]2C5H3N}MBr2 (M = Mn, Fe, Co, Ni, Cu, Zn), 1-6, were characterized by single crystal X-ray structural studies revealing complexes with pentacoordinate distorted square pyramidal coordination environments. This assembly of complexes provided a unique array for examining the relationship between experimental structure and computed electronic structure.

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The aluminum(I) compound NacNacAl (1) reacts with diphenyl disulfide and diethyl sulfide to form the respective four-coordinate bis(phenyl sulfide) complex NacNacAl(SPh)2 (2) and alkyl thiolate aluminum complex NacNacAlEt(SEt) (3). As well, reaction of 1 with tetraphenyl diphosphine furnishes the bis(diphenyl phosphido) complex NacNacAl(PPh2)2 (4). Production of 3 and 4 are the first examples of C(sp(3))-S and R2P-PR2 activation by a main-group element complex.

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Stepwise reduction of the diiminopyridine (dimpyr) complex, dimpyrZnCl2, by KC8 leads to molecular zinc compounds dimpyrZnCl (2) and dimpyrZnCl(DMAP) (3, DMAP = 4-dimethylaminopyridine), which were characterized by X-ray diffraction and EPR spectroscopy. Compound 2 shows an unusual nearly square planar geometry of the zinc atom equally ligated by two imine groups. X-ray crystallographic and EPR data suggest significant delocalization of the zinc 4p electron onto the non-innocent dimpyr ligand.

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New complexes, Mn{κ(3)-[2,6-{Ph2PNMe}2(NC5H3)]}(CO)3(+)Br(-) (1(+)Br(-)) and MnBr{κ(2)-(Ph2P)NMe(NC5H4)}(CO)3 (2), are reported and present new ligand environments for CO2 electrocatalytic reduction to CO. Compound 1(+) presents a unique metal geometry for CO production (96%) in the absence of added water while 2 required addition of water and generated both CO and H2 products.

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A series of iron centered complexes, namely, [Fe(Py2TTA)Cl2] (1), [Fe(Py2TTA)Br2] (2), and [Fe(μ-F)(Py2TTAO)F]∞ (3), were isolated via complexation of 3,5-bis(2-pyridyl)-1,2,4,6-thiatriazine (Py2TTAH) with various ferric halides (e.g., FeF3, FeCl3, and FeBr3).

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The organometallic and coordination chemistry of rhenium(i) has been largely restricted to bidentate α-diimine ligation and facial tricarbonyl coordination geometries. The thermal transformation of bidentate bis(imino)pyridine and bidentate terpyridine complexes at 200-240 °C under nitrogen led to a family of Re(i) pincer complexes [κ(3)-2,6-{ArN[double bond, length as m-dash]CMe}2(NC5H3)]Re(CO)2X (Ar[double bond, length as m-dash]C6H5, Me2C6H3, (i)Pr2C6H3; X = Cl, Br) and (κ(3)-terpy)Re(CO)2X (X = Cl, Br). The synthesis, single crystal X-ray structural and spectroscopic characterization of these eight species documents their Re coordination geometries and demonstrates the accessibility of such compounds.

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Selective reactions between nucleophilic N,N'-diaryl-heterocyclic carbenes (NHCs) and electrophilic fluorinated alkenes afford NHC fluoroalkenes in high yields. These stable compounds undergo efficient and selective fluoride abstraction with Lewis acids to give polyfluoroalkenyl imidazolium salts. These salts react at Cβ with pyrrolidine to give ammonium fluoride-substituted salts, which give rise to conjugated imidazolium-enamine salts through loss of HF.

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Coordinatively unsaturated Fe(III) metal sites were successfully incorporated into the iconic MOF-5 framework. This new structure, Fe(III) -iMOF-5, is the first example of an interpenetrated MOF linked through intercalated metal ions. Structural characterization was performed with single-crystal and powder XRD, followed by extensive analysis by spectroscopic methods and solid-state NMR, which reveals the paramagnetic ion through its interaction with the framework.

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The new tridentate ligand, S(Me)N(H)S = 2-(2-methylthiophenyl)benzothiazolidine, prepared in a single step from commercial precursors in excellent yield, undergoes ring-opening on treatment with Fe(OTf)2 in the presence of base affording a trinuclear iron complex, [Fe3(μ2-S(Me)NS(-))4](OTf)2 (1) which is fully characterized by structural and spectroscopic methods. X-ray structural data reveal that 1 contains four S(Me)NS(-) ligands meridionally bound to two pseudooctahedral iron centers each bridged by two thiolates to a distorted tetrahedral central iron. The combined spectroscopic (UV-vis, Mössbauer, NMR), magnetic (solution and solid state), and computational (DFT) studies indicate that 1 includes a central, high-spin Fe(II) (S = 2) with two low-spin (S = 0) peripheral Fe(II) centers.

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The syntheses of novel Group 5 and Group 6 hydrosilylamido complexes of the type R(ArN[double bond, length as m-dash])M{N((t)Bu)SiMe2-H}X (M = Ta, R = Cp; M = Mo, R = ArN; X = Cl, H, OBn, Me) are described. The various substituents in the X position seem to play the key role in determining the extent of β-agostic interaction with the Si-H bond. The Mo agostic hydrido complex (ArN[double bond, length as m-dash])2Mo{η(3)-N((t)Bu)SiMe2-H}H is a pre-catalyst for the hydrosilylation of carbonyls.

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Four perfluoroalkyl cobalt(III) fluoride complexes have been synthesized and characterized by elemental analysis, multinuclear NMR spectroscopy, X-ray crystallography, and powder X-ray diffraction. The remarkable cobalt fluoride (19)F NMR chemical shifts (-716 to -759 ppm) were studied computationally, and the contributing paramagnetic and diamagnetic factors were extracted. Additionally, the complexes were shown to be active in the catalytic fluorination of p-toluoyl chloride.

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Reaction of complex [CpRu(pyr)3][PF6] (3) with the NHC carbene IPr (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) results in the NHC complex [Cp(IPr)Ru(pyr)2][PF6] (4), which was studied by NMR specroscopy and X-ray diffraction analysis. Reaction of [Cp(IPr)Ru(pyr)2][PF6] (4) with LiAlH4 leads to the trihydride Cp(IPr)RuH3 (5) characterised by spectroscopic methods. Heating compound 5 with hydrosilanes gives the dihydrido silyl derivatives Cp(IPr)RuH2(SiR3) (6).

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A Dy2 complex, exhibiting SMM behaviour, and its Y analogue were prepared via in situ oxidation of Py2TTA, a pincer type ligand, followed by dimerisation. This unique metal complexation and subsequent dimerization were followed by solution NMR studies.

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A Gadolinium EDTA chelate displays characteristic isotropic behaviour common of Gd(III) complexes under zero applied magnetic field, and anisotropic behaviour arising from dipolar coupling and weak spin-phonon coupling under an applied magnetic field. This surprising magnetic behaviour for Gd(III) is investigated using SQUID magnetometry and rationalized through theoretical calculations.

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