A Highly-Reduced Cobalt Terminal Carbyne: Divergent Metal- and α-Carbon-Centered Reactivity

Mokhtarzadeh, Charles C.; Moore, Curtis E.; Rheingold, Arnold L.; Figueroa, Joshua S.

doi:10.1021/jacs.8b05019

Cited by 17 publications

(22 citation statements)

References 42 publications

(108 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The molecular structure of 3-Co is shown in Figure , and it represents, to the best of our knowledge, the first structurally authenticated cobalt(II) species featuring a one-legged piano stool geometry around the metal atom. Nevertheless, isostructural cobalt(I) and cobalt(III) complexes have recently been reported. , Interestingly, the Cp’ cent –Co distance is significantly elongated to 1.84 Å compared to 1-Co , which can be attributed to a spin state change from a low-spin ( S = 1/2) to a high-spin system ( S = 3/2). This is caused by the steric repulsion between the Cp’ and the bis(trimethylsilyl)amido ligands, which supports the formation of the high-spin isomer.…”

Section: Resultsmentioning

confidence: 99%

“…Nevertheless, isostructural cobalt(I) and cobalt(III) complexes have recently been reported. 90,91 Interestingly, the Cp' cent −Co distance is significantly elongated to 1.84 Å compared to 1-Co, which can be attributed to a spin state change from a low-spin (S = 1/2) to a high-spin system (S = 3/2). This is caused by the steric repulsion between the Cp' and the bis(trimethylsilyl)amido ligands, which supports the formation of the high-spin isomer.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Pogo-Stick Iron and Cobalt Complexes: Synthesis, Structures, and Magnetic Properties

et al. 2019

View full text Add to dashboard Cite

The synthesis, structures, and magnetic properties of monomeric half-sandwich iron and cobalt imidazolin-2-iminato complexes have been comprehensively investigated. Salt metathesis reactions of [Cp'M(μ-I)] 2 (1-M, M = Fe, Co; Cp' = η 5 -1,2,4-tri-tertbutylcyclopentadienyl) with [Im Dipp NLi] 2 (Im Dipp N = 1,3-bis(2,6diisopropylphenyl)imidazolin-2-iminato) furnishes the terminal halfsandwich compounds [Cp'M(NIm Dipp )] (2-M, M = Fe, Co), which can be regarded as models for elusive half-sandwich iron and cobalt imido complexes. X-ray diffraction analysis confirmed the structure motif of a one-legged piano stool. Complex 2-Co can also be prepared by an acid−base reaction between [Cp'Co{N(SiMe 3 ) 2 }] (3-Co) and Im Dipp NH. The electronic and magnetic properties of 2-M and 3-Co were probed by 57 Fe Mossbauer spectroscopy (M = Fe), X-band EPR spectroscopy (M = Co), and solid-state magnetic susceptibility measurements. In particular, the central metal atom adopts a high-spin (S = 2) state in 2-Fe, while the cobalt complex 2-Co represents a rare example of a Co(II) species with a coordination number different from six displaying a low-spin to high-spin spin-crossover (SCO) behavior. The experimental observations are complemented by DFT calculations.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: ■ Results and Discussionmentioning

confidence: 99%

Pogo-Stick Iron and Cobalt Complexes: Synthesis, Structures, and Magnetic Properties

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Recently, we reported an approach to overcoming this challenge by using the rigid and linear ditopic m -terphenyl diisocyanide, [CNAr Mes2 ] 2 , as a linker group (Ar Mes2 = 2,6-(2,4,6-Me 3 C 6 H 2 ) 2 C 6 H 3 ; Scheme ). , Isocyanide ligands have long been recognized for their ability to function as both good σ-donors and strong π-acids, − which are properties that are particularly advantageous for the stabilization of electron-rich metal centers. − Accordingly, despite their charge neutrality, the dual bonding interactions provided by isocyanides lead to strong metal–ligand linkages that can be harnessed for reticular network formation. ,, It was shown that [CNAr Mes2 ] 2 could provide a series of robust, single-crystalline frameworks featuring Cu(I)-based single-metal structural nodes (i.e., Cu- ISO CNs 1–3; ISO CN = isocyanide coordination network; Scheme ). In certain cases, these frameworks retain their thermal integrity up to ca.…”

Section: Introductionmentioning

confidence: 99%

Aqueous Stability and Ligand Substitution of a Layered Cu(I)/Isocyanide-Based Organometallic Network Material with a Well-Defined Channel Structure

et al. 2020

Self Cite

View full text Add to dashboard Cite

Isocyanide coordination networks (ISOCNs), which consist of multitopic isocyanide linker groups and transition-metal-based secondary building units (SBUs), are a promising class of organometallic framework materials for the inclusion of low-valent metal centers as primary structural components. Previously, it was demonstrated that the ditopic m-terphenyl isocyanide ligand, [CNArMes2]2 (ArMes2 = 2,6-(2,4,6-Me3C6H2)2C6H3), could provide single-metal node frameworks based on Cu(I) and Ni(0) centers. However, the relatively short linker length in [CNArMes2]2 precluded the formation of networks with significant porosity. Here, it is shown that expansion of the [CNArMes2]2 scaffold with a central phenylene spacer allows for the formation of a robust Cu(I)-based framework with a distinct and solvent accessible channel structure. This new framework, denoted Cu-ISOCN-4, is prepared as single-crystalline samples from a solvothermal reaction between [Cu(NCMe)4]PF6 and expanded linker 1,4-(CNArMes2)2C6H4. Crystallographic characterization of Cu-ISOCN-4 revealed mononuclear [Cu(THF)(CNR)3]+ structural nodes. The expanded diisocyanide linker results in fourfold interpenetrated (6,3) internal morphology. However, interpenetration in Cu-ISOCN-4 results in discrete layer domains, each of which possesses well-defined 29 × 19 Å channels along the crystallographic b axis. Thermogravimetric analysis on Cu-ISOCN-4 revealed THF solvent loss from the channels between 100–200 °C and dissociation of the Cu-coordinated THF ligand at 290 °C. The overall integrity of the network remains intact up to 400 °C, thereby signifying the robust nature of materials produced from metal-isocyanide M-C linkages. Aqueous stability studies revealed that Cu-ISOCN-4 remains chemically resistant to exposure to liquid water for several days. In addition, ligand exchange studies in both THF and aqueous solution demonstrate that the Cu-coordinated THF group in Cu-ISOCN-4 can be readily substituted with pyridine. This ligand exchange process occurs via single-crystal-to-single-crystal transformations and can also be readily monitored by infrared spectroscopy.

show abstract

“…4), a series of reactant osmapentalynes (1b-1g) were synthesized by the treatment of carbon ligands (L2-L7) with multiyne chains with OsCl 2 (PPh 3 ) 3 and PPh 3 , the different substituents at different positions appear not to affect the reaction (3,(31)(32)(33)(34)(35)(36). For instance, the R′ substituent can be styryl (3), phenyl (31)(32)(33), thienyl (34) or hydrogen (35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46), and the Y group can be CH 2 (31,34), O (32,35) or C(COOMe) 2 (33,36). The structures of all the above complexes were confirmed by NMR spectroscopy, EA and HRMS ( Supplementary Figs.…”

Section: Resultsmentioning

confidence: 99%

“…The reactions of M≡C and C≡C bonds tend to afford cycloaddition intermediates or products on account of their high degree of unsaturation. For example, the alkyne metathesis undergoes metallacyclobutadiene intermediates process 12-14 , and [2+2], [2+2+1], and [2+2+2] cycloaddition products have been widely published [26][27][28][29][30][31][32][33][34][35][36][37] . Acyclic products, however, have never been reported.…”

mentioning

confidence: 99%

Addition of alkynes and osmium carbynes towards functionalized dπ–pπ conjugated systems

et al. 2020

View full text Add to dashboard Cite

The metal-carbon triple bonds and carbon-carbon triple bonds are both highly unsaturated bonds. As a result, their reactions tend to afford cycloaddition intermediates or products. Herein, we report a reaction of M≡C and C≡C bonds that affords acyclic addition products. These newly discovered reactions are highly efficient, regio- and stereospecific, with good functional group tolerance, and are robust under air at room temperature. The isotope labeling NMR experiments and theoretical calculations reveal the reaction mechanism. Employing these reactions, functionalized dπ-pπ conjugated systems can be easily constructed and modified. The resulting dπ-pπ conjugated systems were found to be good electron transport layer materials in organic solar cells, with power conversion efficiency up to 16.28% based on the PM6: Y6 non-fullerene system. This work provides a facile, efficient methodology for the preparation of dπ-pπ conjugated systems for use in functional materials.

show abstract

A Highly-Reduced Cobalt Terminal Carbyne: Divergent Metal- and α-Carbon-Centered Reactivity

Cited by 17 publications

References 42 publications

Pogo-Stick Iron and Cobalt Complexes: Synthesis, Structures, and Magnetic Properties

Pogo-Stick Iron and Cobalt Complexes: Synthesis, Structures, and Magnetic Properties

Aqueous Stability and Ligand Substitution of a Layered Cu(I)/Isocyanide-Based Organometallic Network Material with a Well-Defined Channel Structure

Addition of alkynes and osmium carbynes towards functionalized dπ–pπ conjugated systems

Contact Info

Product

Resources

About