skip to main content


Title: Dispersion‐Force‐Assisted Disproportionation: A Stable Two‐Coordinate Copper(II) Complex
Abstract

The synthesis of the first linear coordinated CuIIcomplex Cu{N(SiMe3)Dipp}2(1Dipp=C6H5‐2,6Pri2) and its CuIcounterpart [Cu{N(SiMe3)Dipp}2](2) is described. The formation of1proceeds through a dispersion force‐driven disproportionation, and is the reaction product of a CuIhalide and LiN(SiMe3)Dipp in a non‐donor solvent. The synthesis of2is accomplished by preventing the disproportionation into1by using the complexing agent 15‐crown‐5. EPR spectroscopy of1provides the first detailed study of a two‐coordinate transition‐metal complex indicating strong covalency in the Cu−N bonds.

 
more » « less
PAR ID:
10236578
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Angewandte Chemie
Volume:
128
Issue:
35
ISSN:
0044-8249
Page Range / eLocation ID:
p. 10600-10603
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Abstract

    Reactions of the IrVhydride [MeBDIDipp]IrH4{BDI=(Dipp)NC(Me)CH(Me)CN(Dipp); Dipp=2,6‐iPr2C6H3} with E[N(SiMe3)2]2(E=Sn, Pb) afforded the unusual dimeric dimetallotetrylenes ([MeBDIDipp]IrH)2(μ2‐E)2in good yields. Moreover, ([MeBDIDipp]IrH)2(μ2‐Ge)2was formed in situ from thermal decomposition of [MeBDIDipp]Ir(H)2Ge[N(SiMe3)2]2. These reactions are accompanied by liberation of HN(SiMe3)2and H2through the apparent cleavage of an E−N(SiMe3)2bond by Ir−H. In a reversal of this process, ([MeBDIDipp]IrH)2(μ2‐E)2reacted with excess H2to regenerate [MeBDIDipp]IrH4. Varying the concentrations of reactants led to formation of the trimeric ([MeBDIDipp]IrH2)3(μ2‐E)3. The further scope of this synthetic route was investigated with group 15 amides, and ([MeBDIDipp]IrH)2(μ2‐Bi)2was prepared by the reaction of [MeBDIDipp]IrH4with Bi(NMe2)3or Bi(OtBu)3to afford the first example of a “naked” two‐coordinate Bi atom bound exclusively to transition metals. A viable mechanism that accounts for the formation of these products is proposed. Computational investigations of the Ir2E2(E=Sn, Pb) compounds characterized them as open‐shell singlets with confined nonbonding lone pairs at the E centers. In contrast, Ir2Bi2is characterized as having a closed‐shell singlet ground state.

     
    more » « less
  2. Abstract

    A family of cerium complexes featuring a redox‐active ligand in different oxidation states has been synthesized, including the the iminosemiquinone (isq)1−compound, Ce(dippisq)3(1‐Ceisq), and the amidophenolate (ap)2−species CeIII(dippap)3K3(2‐Ceap), [CeIII(dippap)3K][K(18‐c‐6)]2(2‐Ceap 18c6), and [CeIII(dippap)3K][K(15‐c‐5)2]2(2‐Ceap 15c5). Treating2‐Ceap 15c5with dioxogen furnishes the cerium(IV) derivative [CeIV(dippap)3][K(15‐c‐5)2]2(3‐Ceap 15c5), and an analogous synthesis can be used to generate [CeIV(dippap)3][K(crypt)]2(3‐Ceap crypt). Similarly, addition of hexamethyldisiloxane produces an interesting bis(amidophenolate) species, [(Me3SiO)2CeIV(dippap)2][K(15‐c‐5)2]2(4‐CeOSiMe3). Full spectroscopic and structural characterization of each derivative was performed to establish the oxidation states of both the ligands and the cerium ions.

     
    more » « less
  3. Not, available (Ed.)
    Abstract

    Described here is a direct entry to two examples of 3d transition metal catalysts that are active for the cyclic polymerization of phenylacetylene, namely, [(BDI)M{κ2C,C‐(Me3SiC3SiMe3)}] (2‐M) (BDI=[ArNC(CH3)]2CH, Ar=2,6‐iPr2C6H3;M=Ti, V). Catalysts are prepared in one step by the treatment of [(BDI)MCl2] (1‐M,M=Ti,V) with 1,3‐dilithioallene [Li2(Me3SiC3SiMe3)]. Complexes2‐Mhave been spectroscopically and structurally characterized and the polymers that are catalytically formed from phenylacetylene were verified to have a cyclic topology based on a combination of size‐exclusion chromatography (SEC) and intrinsic viscosity studies. Two‐electron oxidation of2‐Vwith nitrous oxide (N2O) cleanly yields a [VV] alkylidene‐alkynyl oxo complex [(BDI)V(=O){κ1C‐(=C(SiMe3)CC(SiMe3))}] (3), which lends support for how this scaffold in2‐Mmight be operating in the polymerization of the terminal alkyne. This work demonstrates how alkylidynes can be circumvented using 1,3‐dianionic allene as a segue into M−C multiple bonds.

     
    more » « less
  4. Abstract

    Herein we combine the subcomponent self‐assembly and integrative self‐sorting techniques with the well‐established platinum(II)‐pyridine coordination‐driven self‐assembly to report the quantitative synthesis and spectroscopic characterization of a heterometallic CuI‐PtIIquadrilateralQLthat is formed from a total of twelve molecular components from four unique species, including 5‐(pyridin‐4‐ylethynyl)picolinaldehyde (1),p‐toluidine (2), [Cu(CH3CN4](PF6) (3), andcis‐Pt(PEt3)2(OTf)2(4), in a 4:4:2:2 ratio. Despite the many different entities potentially forming from these four precursor units, the clean formation ofQLis mainly guided by the different coordination preferences of the metal ions3and4, and the design criteria inherent in compounds1and2.

     
    more » « less
  5. Abstract

    This computational study explores the copper (I) chloride catalyzed synthesis of (E)‐1‐(2,2‐dichloro‐1‐phenylvinyl)‐2‐phenyldiazene (2Cl‐VD) from readily available hydrazone derivative and carbon tetrachloride (CCl4).2Cl‐VDhas been extensively utilized to synthesize variety of heterocyclic organic compounds in mild conditions. The present computational investigations primarily focus on understanding the role of copper (I) andN1,N1,N2,N2‐tetramethylethane‐1,2‐diamine (TMEDA) in this reaction, TMEDA often being considered a proton scavenger by experimentalists. Considering TMEDA as a ligand significantly alters the energy barrier. In fact, it is only 8.3 kcal/mol higher compared to the ligand‐free (LF) route for the removal of a chlorine atom to form the radical·CCl3but the following steps are almost barrierless. This intermediate then participates in attacking the electrophilic carbon in the hydrazone. Crucially, the study reveals that the overall potential energy surface is thermodynamically favorable, and the theoretical turnover frequency (TOF) value is higher in the case of Cu(I)‐TMEDA complex catalyzed pathway.

     
    more » « less