Computational Studies of Structures and Properties of Metallaboranes. 2. Transition-Metal Dicarbollide Complexes

Bühl, Michæl; Holub, Josef; Hnyk, Drahomı́r; Macháček, Jan

doi:10.1021/om051025f

Cited by 48 publications

(25 citation statements)

References 68 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Akey feature in the COSAN anion is that the BÀH/CÀH bonds tilt away from the C 2 B 3 layer towards the metal that prevents free rotation, [14] thus producing three main rotameric forms of different energy,a ss hown in Figure 1, in which the cis and gauche rotamers are able to have clockwise and counterclockwise forms.The transoid rotamer is the one with lower energy "in vacuo", as shown by quantum chemical calculations. [15,16] However,aprevious study conducted by some of us [12] found that this rotamer is only present at about 8% in crystal structures with the composition M[Co-(C 2 B 9 H 11 ) 2 ]. Largely,t he most abundant rotamer in the solid state is the cis rotamer ( Table 1).…”

mentioning

confidence: 99%

Atomistic Simulations of COSAN: Amphiphiles without a Head‐and‐Tail Design Display “Head and Tail” Surfactant Behavior

et al. 2020

View full text Add to dashboard Cite

Cobaltabisdicarbollide (COSAN) anions have an unexpectedly rich self‐assembly behavior, which can lead to vesicles and micelles without having a classical surfactant molecular architecture. This was rationalized by the introduction of new terminology and novel driving forces. A key aspect in the interpretation of COSAN behavior is the assumption that the most stable form of these ions is the transoid rotamer, which lacks a “hydrophilic head” and a “hydrophobic tail”. Using implicit solvent DFT calculations and MD simulations we show that in water, 1) the cisoid rotamer is the most stable form of COSAN and 2) this cisoid rotamer has a well‐defined hydrophilic polar region (“head”) and a hydrophobic apolar region (“tail”). In addition, our simulations show that the properties of this rotamer in water (interfacial affinity, micellization) match those expected for a classical surfactant. Therefore, we conclude that the experimental results for the COSAN ions can now be understood in terms of its amphiphilic molecular architecture.

show abstract

mentioning

confidence: 99%

Atomistic Simulations of COSAN: Amphiphiles without a Head‐and‐Tail Design Display “Head and Tail” Surfactant Behavior

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Preferability of different conformations depend on the nature of the metal and its oxidation state [ 59 , 60 , 61 ]. Thus, the transoid conformation is preferred in the case of nickel(III) bis(dicarbollide), whereas for nickel(IV) bis(dicarbollide) the cisoid conformation with the rotation angle about 36° is the most stable ( Figure 21 ) [ 61 ].…”

Section: Transition Metal Bid(dicarbollide) Based Molecular Switchmentioning

confidence: 99%

Ferrocene and Transition Metal Bis(Dicarbollides) as Platform for Design of Rotatory Molecular Switches

Sivaev

2017

Molecules

View full text Add to dashboard Cite

Design of rotatory molecular switches based on extremely stable sandwich organometallic complexes ferrocene and bis(dicarbollide) complexes of transition metals is reviewed. The “on”–“off” switching in these systems can be controlled by various external stimuli such as change of the solution pH, interactions with coordinating species or redox reactions involving the central atom or substituents in the ligands.

show abstract

“…Fig.1, which is the most probable conformer in aqueous solution, is close to a C 2v symmetry. 36,37 In such a case three independent components are expected to dominate the hyperpolarisability tensor: β xxz , β xzx and β zxx . Therefore Eq.…”

Section: Determination Of χ (2) As Function Of [Cosan] -Adsorbed Ontomentioning

confidence: 99%

Surface Activity and Molecular Organization of Metallacarboranes at the Air–Water Interface Revealed by Nonlinear Optics

et al. 2015

View full text Add to dashboard Cite

Because of their amphiphilic structure, surfactants adsorb at the water-air interface with their hydrophobic tails pointing out of the water and their polar heads plunging into the liquid phase. Unlike classical surfactants, metallabisdicarbollides (MCs) do not have a well-defined amphiphilic structure. They are nanometer-sized inorganic anions with an ellipsoidal shape composed of two carborane semicages sandwiching a metal ion. However, MCs have been shown to share many properties with surfactants, such as self-assembly in water (formation of micelles and vesicles), formation of lamellar lyotropic phases, and surface activity. By combining second harmonic generation and surface tension measurement, we show here that cobaltabis(dicarbollide) anion {[(C2B9H11)2Co](-) also named [COSAN](-)} with H(+) as a counterion, the most representative metallacarborane, adsorbs vertically at the water surface with its long axis normal to the surface. This vertical molecular orientation facilitates the formation of intermolecular and nonconventional dihydrogen bonds such as the B-H(δ-)···(δ+)H-C bond that has recently been proven to be at the origin of the self-assembly of MCs in water. Therefore, it appears here that lateral dihydrogen bonds are also involved in the surface activity of MCs.

show abstract

Computational Studies of Structures and Properties of Metallaboranes. 2. Transition-Metal Dicarbollide Complexes

Cited by 48 publications

References 68 publications

Atomistic Simulations of COSAN: Amphiphiles without a Head‐and‐Tail Design Display “Head and Tail” Surfactant Behavior

Atomistic Simulations of COSAN: Amphiphiles without a Head‐and‐Tail Design Display “Head and Tail” Surfactant Behavior

Ferrocene and Transition Metal Bis(Dicarbollides) as Platform for Design of Rotatory Molecular Switches

Surface Activity and Molecular Organization of Metallacarboranes at the Air–Water Interface Revealed by Nonlinear Optics

Contact Info

Product

Resources

About