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Luff MS, Walther L, Finze M, Radius U. NHC-ligated nickel(II) cyanoborate complexes and salts. Dalton Trans 2024; 53:5391-5400. [PMID: 38415451 DOI: 10.1039/d4dt00231h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
A comprehensive study on the synthesis and characterization of NHC-ligated nickel(II) cyanoborates (CBs) is presented (NHC = N-heterocyclic carbene). Nickel(II) cyanoborates Ni[BH2(CN)2]2·H2O (Ib·H2O), Ni[BH(CN)3]2·0.5H2O (Ic·0.5H2O), Ni[B(CN)4]2·H2O (Id·H2O) were reacted with selected NHCs of different steric size. The reaction of the nickel cyanoborates with small to medium-sized NHCs Me2ImMe and iPr2Im (R2Im = 1,3-di-organyl-imidazolin-2-ylidene; R2ImMe = 1,3-di-organyl-4,5-dimethyl-imidazolin-2-ylidene) afforded cyanoborate salts containing the rare homoleptic fourfold NHC-ligated nickel(II) cations [Ni(NHC)4]2+ (NHC = Me2ImMe (1c-d), iPr2Im (2c-d)) and cyanoborate counter-anions. Bulkier NHCs such as Mes2Im and Dipp2Im afforded complexes trans-[Ni(NHC)2(CB)2] (trans-4b, trans-5c). For the combination of the cyanoborate anion [BH2(CN)2]- and iPr2ImMe the salt of the tris-NHC complex [Ni(iPr2ImMe)3(NC-BH2CN)][BH2(CN)2] (3b) was isolated. Salt metathesis of NHC-ligated nickel(II) halides (Ni(NHC)2X2) (X = Cl, Br) with silver(I) and alkali metal cyanoborates were used to synthesize mono- and disubstituted coordination compounds of the type cis- or trans-[Ni(NHC)2(CB)X] (cis-10c, cis-11c, trans-12b) and cis- or trans-[Ni(NHC)2(CB)2] (cis-13b, cis-14a-c, trans-14a-b, trans-15b, trans-5b). Further investigations reveal that NHC-ligated cyanoborate complexes can act as building blocks for coordination polymers, as observed for structurally characterized 1∞{trans-[Ni(Mes2Im)2(μ2-[NC-BH2-CN])2]·2Ag(μ2-[BH2(CN)2])} (trans-5b·Ag). This study demonstrates the diverse character of cyanoborates in coordination chemistry as both, non-coordinating counter-anions, and weakly to medium coordinating anions forming novel transition metal complexes and salts. It provides evidence that a proper choice of cyanoborate and a proper choice of co-ligand can lead to a rich coordination chemistry of cyanoborate anions.
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Affiliation(s)
- Martin S Luff
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Luis Walther
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Maik Finze
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Udo Radius
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
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Tendera L, Kuehn L, Marder TB, Radius U. On the Reactivity of a NHC Nickel Bis-Boryl Complex: Reductive Elimination and Formation of Mono-Boryl Complexes. Chemistry 2023; 29:e202302310. [PMID: 37551752 DOI: 10.1002/chem.202302310] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/07/2023] [Accepted: 08/08/2023] [Indexed: 08/09/2023]
Abstract
The synthesis of the first terminal mono-boryl complexes of nickel, which are not stabilized by a pincer ligand, is reported. The reaction of the nickel bis-boryl complex cis-[Ni(i Pr2 ImMe )2 (Bcat)2 ] 1 (cat=1,2-O2 C6 H4 ) with the small donor ligand PMe3 led to a complete ligand exchange at nickel with reductive elimination of B2 cat2 and formation of the bis-NHC adduct [B2 cat2 ⋅ (i Pr2 ImMe )2 ] 3 and [Ni(PMe3 )4 ] 2 as the metal-containing species. Electrophilic attack of MeI on complex 1 or ligand dismutation of 1 with trans-[Ni(i Pr2 ImMe )2 Br2 ] led to loss of only one boryl ligand of 1 and afforded the nickel mono-boryl complexes trans-[Ni(i Pr2 ImMe )2 (Bcat)Br] 4 a and trans-[Ni(i Pr2 ImMe )2 (Bcat)I] 4 b.
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Affiliation(s)
- Lukas Tendera
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Laura Kuehn
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Todd B Marder
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Udo Radius
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
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Horrer G, Luff MS, Radius U. N-Heterocyclic carbene and cyclic (alkyl)(amino)carbene ligated half-sandwich complexes of chromium(II) and chromium(I). Dalton Trans 2023; 52:13244-13257. [PMID: 37667868 DOI: 10.1039/d3dt02123h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
Abstract
The synthesis and characterization of a series of Cr(II) N-Heterocyclic Carbene (NHC) complexes of the type [{Cr(NHC)Cl(μ-Cl)}2] and [(Cyp)Cr(NHC)X] (Cyp = η5-C5H5, cyclopentadienyl; η5-C5Me5, pentamethylcyclopentadienyl; X = Cl, η3-C3H5; NHC = IMeMe, IiPrMe, IMes, IDipp) as well as the cyclic (alkyl)(amino)carbene cAACMe ligated complexes [(η5-C5H5)Cr(cAACMe)X] (X = Cl, NPh2), [(η5-C9H7)Cr(cAACMe)Cl] (C9H7 = Ind, indenyl) and [(η5-C13H9)Cr(cAACMe)Cl] (C13H9 = Fl, fluorenyl) are reported. The reduction of [(η5-C5Me5)Cr(IMeMe)Cl] with KC8 in the presence of CO afforded the NHC ligated Cr(I) metallo-radical [(η5-C5Me5)Cr(IMeMe)(CO)2]. Quantum chemical calculations performed on [(η5-C5Me5)Cr(IMeMe)(CO)2] confirm for this complex a predominantly chromium centered radical.
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Affiliation(s)
- Günther Horrer
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Martin S Luff
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Udo Radius
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
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Thangavadivale VG, Tendera L, Bertermann R, Radius U, Beweries T, Perutz RN. Solution and solid-state studies of hydrogen and halogen bonding with N-heterocyclic carbene supported nickel(II) fluoride complexes. Faraday Discuss 2023; 244:62-76. [PMID: 37097153 DOI: 10.1039/d2fd00171c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Nickel fluoride complexes of the type [Ni(F)(L)2(ArF)] (L = phosphine, ArF = fluorinated arene) are well-known to form strong halogen and hydrogen bonds in solution and in the solid state. A comprehensive study of such non-covalent interactions using bis(carbene) complexes as acceptors and suitable halogen and hydrogen bond donors is presented. In solution, the complex [Ni(F)(iPr2Im)2(C6F5)] forms halogen and hydrogen bonds with iodopentafluorobenzene and indole, respectively, which have formation constants (K300) an order of magnitude greater than those of structurally related phosphine supported nickel fluorides. Co-crystallisation of this complex and its backbone-methylated analogue [Ni(F)(iPr2Me2Im)2(C6F5)] with 1,4-diiodotetrafluorobenzene produces halogen bonding adducts which were characterised by X-ray analysis and 19F MAS solid state NMR analysis. Differences in the chemical shifts between the nickel fluoride and its halogen bonding adduct are well in line with data that were obtained from titration studies in solution.
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Affiliation(s)
| | - Lukas Tendera
- Institut für Anorganische Chemie, Julius-Maximilians-Universität, Am Hubland, 97074 Würzburg, Germany.
| | - Rüdiger Bertermann
- Institut für Anorganische Chemie, Julius-Maximilians-Universität, Am Hubland, 97074 Würzburg, Germany.
| | - Udo Radius
- Institut für Anorganische Chemie, Julius-Maximilians-Universität, Am Hubland, 97074 Würzburg, Germany.
| | - Torsten Beweries
- Leibniz-Institut für Katalyse, Albert-Einstein-Str. 29a, 18059 Rostock, Germany.
| | - Robin N Perutz
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK.
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Tendera L, Fantuzzi F, Marder TB, Radius U. Nickel boryl complexes and nickel-catalyzed alkyne borylation. Chem Sci 2023; 14:2215-2228. [PMID: 36845942 PMCID: PMC9945561 DOI: 10.1039/d2sc04690c] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 01/27/2023] [Indexed: 01/28/2023] Open
Abstract
The first nickel bis-boryl complexes cis-[Ni( i Pr2ImMe)2(Bcat)2], cis-[Ni( i Pr2ImMe)2(Bpin)2] and cis-[Ni( i Pr2ImMe)2(Beg)2] are reported, which were prepared via the reaction of a source of [Ni( i Pr2ImMe)2] with the diboron(4) compounds B2cat2, B2pin2 and B2eg2 ( i Pr2ImMe = 1,3-di-iso-propyl-4,5-dimethylimidazolin-2-ylidene; B2cat2 = bis(catecholato)diboron; B2pin2 = bis(pinacolato)diboron; B2eg2 = bis(ethylene glycolato)diboron). X-ray diffraction and DFT calculations strongly suggest that a delocalized, multicenter bonding scheme dictates the bonding situation of the NiB2 moiety in these square planar complexes, reminiscent of the bonding situation of "non-classical" H2 complexes. [Ni( i Pr2ImMe)2] also efficiently catalyzes the diboration of alkynes using B2cat2 as the boron source under mild conditions. In contrast to the known platinum-catalyzed diboration, the nickel system follows a different mechanistic pathway, which not only provides the 1,2-borylation product in excellent yields, but also provides an efficient approach to other products such as C-C coupled borylation products or rare tetra-borylated compounds. The mechanism of the nickel-catalyzed alkyne borylation was examined by means of stoichiometric reactions and DFT calculations. Oxidative addition of the diboron reagent to nickel is not dominant; the first steps of the catalytic cycle are coordination of the alkyne to [Ni( i Pr2ImMe)2] and subsequent borylation at the coordinated and, thus, activated alkyne to yield complexes of the type [Ni(NHC)2(η2-cis-(Bcat)(R)C[double bond, length as m-dash]C(R)(Bcat))], exemplified by the isolation and structural characterization of [Ni( i Pr2ImMe)2(η2-cis-(Bcat)(Me)C[double bond, length as m-dash]C(Me)(Bcat))] and [Ni( i Pr2ImMe)2(η2-cis-(Bcat)(H7C3)C[double bond, length as m-dash]C(C3H7)(Bcat))].
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Affiliation(s)
- Lukas Tendera
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Felipe Fantuzzi
- School of Chemistry and Forensic Science, University of KentPark Wood RdCanterburyCT2 7NHUK
| | - Todd B. Marder
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität WürzburgAm Hubland97074 WürzburgGermany,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität WürzburgAm Hubland97074 WürzburgGermany
| | - Udo Radius
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
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Yang ES, Goicoechea JM. Revealing the Role of the Cyaphide Ion as a Bridging Ligand in Heterometallic Complexes. Angew Chem Int Ed Engl 2022; 61:e202206783. [PMID: 35695304 PMCID: PMC9546431 DOI: 10.1002/anie.202206783] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Indexed: 11/08/2022]
Abstract
The synthesis of heterometallic transition metal complexes featuring bridging cyaphide ions (C≡P−) is reported. These are synthesized from reactions of Au(IDipp)(CP) (IDipp=1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene) with electron‐rich, nucleophilic transition metal reagents, affording Au(IDipp)(μ2−C≡P)Ni(MeIiPr)2 (MeIiPr=1,3‐diisopropyl‐4,5‐dimethylimidazol‐2‐ylidene) and Au(IDipp)(μ2−C≡P)Rh(Cp*)(PMe3). These studies reveal that, in contrast to the cyanide ion, bimetallic cyaphido complexes strongly favor a η1 : η2 coordination mode that maximizes the interaction of the second metal (Ni, Rh) with the π‐manifold of the ion (and not the phosphorus atom lone pair). End‐on bridging can be effectively unlocked by blocking the π‐manifold, as demonstrated by reaction of Au(IDipp)(μ2−C≡P)Rh(Cp*)(PMe3) with an electrophilic transition metal reagent, W(CO)5(THF), which affords the heterotrimetallic compound Au(IDipp)(μ3−C≡P)[Rh(Cp*)(PMe3)][W(CO)5].
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Affiliation(s)
- Eric S. Yang
- Department of Chemistry University of Oxford Chemistry Research Laboratory 12 Mansfield Road Oxford OX1 3TA U.K
| | - Jose M. Goicoechea
- Department of Chemistry University of Oxford Chemistry Research Laboratory 12 Mansfield Road Oxford OX1 3TA U.K
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Tendera L, Krummenacher I, Radius U. Cationic Nickel d9‐Metalloradicals [Ni(NHC)2]+. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Lukas Tendera
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg Anorganische Chemie GERMANY
| | - Ivo Krummenacher
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg Anorganische Chemie GERMANY
| | - Udo Radius
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg Institut für Anorganische Chemie Am Hubland 97074 Würzburg GERMANY
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Horrer G, Krummenacher I, Mann S, Braunschweig H, Radius U. N-Heterocyclic carbene and cyclic (alkyl)(amino)carbene complexes of vanadium(III) and vanadium(V). Dalton Trans 2022; 51:11054-11071. [PMID: 35796195 DOI: 10.1039/d2dt01250b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
[VCl3(THF)3] offers a convenient entrance point into the chemistry of carbene stabilized V(III) complexes. Herein we report the paramagnetic mono- and biscarbene complexes [VCl3(cAACMe)] 1, [VCl3(cAACMe)(THF)] 1(thf), [VCl3(IMes)] 2, [{VCl2(IiPrMe)(μ-Cl)}2] 3, [VCl3(IDipp)] 4, [VCl3(SIDipp)] 5, [VCl3(SIDipp)(THF)] 5(thf), [VCl3(ItBu)] 6, [VCl3(cAACMe)2] 7 and [VCl3(IiPrMe)2] 8. Reaction of 1 with MesMgCl, MesLi and LiNPh2 afforded the complexes [VCl2(Mes)(cAACMe)] 9, [cAACMeH]+[VCl2Mes2]-10 and [VCl2(NPh2)(cAACMe)] 11. The V(V) complexes [V(O)Cl3(IDipp)] 12 and [V(O)Cl3(SIDipp)] 13 were selectively prepared from oxygen oxidation of 4 and 5. [V(O)Cl3(IDipp)] 12 and [V(O)Cl3(IMes)] react with isocyanates to yield the NHC-ligated imido complexes [V(N-p-CH3C6H4)Cl3(IDipp)] 14, [V(N-p-FC6H4)Cl3(IDipp)] 15, [V(N-p-CH3C6H4)Cl3(SIDipp)] 16, [V(N-p-FC6H4)Cl3(SIDipp)] 17, [V(N-p-CH3C6H4)Cl3(IMes)] 18 and [V(N-p-FC6H4)Cl3(IMes)] 19.
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Affiliation(s)
- Günther Horrer
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Ivo Krummenacher
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany. .,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Sophie Mann
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Holger Braunschweig
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany. .,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Udo Radius
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
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Yang ES, Goicoechea JM. Revealing the Role of the Cyaphide Ion as a Bridging Ligand in Heterometallic Complexes. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202206783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Eric S. Yang
- University of Oxford Department of Chemistry UNITED KINGDOM
| | - Jose Manuel Goicoechea
- University of Oxford Department of Chemistry CRL, Mansfield Road OX1 3TA Oxford UNITED KINGDOM
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