Investigation of the Interaction, Rheological and Tribological Properties of Bis(pinacolato)diboron with Lithium Grease

AbstractIn this article, Lewis acid–base complex of lithium 12-hydroxystearate (LHS) with diboron compound is formed by the introduction of bis(pinacolato)diboron (B2Pin2) into lithium grease. The interaction between Lewis acid B2Pin2 and Lewis base RCO2− of LHS is characterized by various techniques. Moreover, the rheological and tribological behaviors of the base grease are evaluated at low and moderate temperature. The results indicate that the addition of B2Pin2 can noticeably enhance the rheological property of the base grease because the formation of Lewis acid–base complex is beneficial for improving the soap fiber structure strength, and B2Pin2 could also help reduce the friction and wear of the grease during the sliding process, which likely owing to the boundary lubrication film generated by B2Pin2 adsorption on the rubbing surface and tribochemical reaction between borate esters and steel surfaces. The improvement of mechanical stability and tribological properties is beneficial to increasing the grease service life. Graphical Abstract

Download Full-text

Investigation of the Interaction, Rheological and Tribological Properties of Bis(pinacolato)diboron with Lithium Grease During Mechanical Aging

10.21203/rs.3.rs-452457/v1 ◽

2021 ◽

Author(s):

Jia Ren ◽

Kuiliang Gong ◽

Gaiqing Zhao ◽

Xinhu Wu ◽

Xiaobo Wang

Keyword(s):

Lewis Acid ◽

Lewis Base ◽

Mechanical Degradation ◽

Fiber Structure ◽

Acid Base ◽

Lithium Grease ◽

Base Complex ◽

Structure Strength ◽

Base Grease ◽

Mechanical Aging

Abstract In this article, Lewis acid–base complex of lithium 12-hydroxystearate (LHS) with diboron compound is formed by the introduction of bis(pinacolato)diboron (B2Pin2) into lithium grease. The interaction between Lewis acid B2Pin2 and Lewis base RCO2− of LHS is characterized by various techniques. Moreover, the rheological and tribological behaviors of the base grease are evaluated at low and moderate temperature, and the results indicate that the addition of B2Pin2 noticeably enhanced the rheological, friction-reducing, and anti-wear (AW) properties of the base grease, which likely owing to the fact that the formation of Lewis acid–base complex is beneficial for improving the soap fiber structure strength, helping to prevent the mechanical degradation of the lithium grease during mechanical aging process.

Download Full-text

Influence of Lewis base HMPA on the properties of efficient planar MAPbI3 solar cells fabricated by one-step process assisted by Lewis acid-base adduct approach

Chemical Engineering Journal ◽

10.1016/j.cej.2019.122436 ◽

2020 ◽

Vol 380 ◽

pp. 122436 ◽

Cited By ~ 6

Author(s):

Kyungeun Jung ◽

Weon-Sik Chae ◽

Yun Chang Park ◽

Joosun Kim ◽

Man-Jong Lee

Keyword(s):

Solar Cells ◽

Lewis Acid ◽

Lewis Base ◽

Acid Base ◽

Step Process ◽

One Step

Download Full-text

Structure investigations of group 13 organometallic carboxylates

Dalton Transactions ◽

10.1039/c6dt03958h ◽

2017 ◽

Vol 46 (3) ◽

pp. 669-677 ◽

Cited By ~ 5

Author(s):

Iwona Justyniak ◽

Daniel Prochowicz ◽

Adam Tulewicz ◽

Wojciech Bury ◽

Piotr Goś ◽

...

Keyword(s):

Molecular Structure ◽

Lewis Acid ◽

Relative Magnitude ◽

Lewis Base ◽

Acid Base ◽

Group 13 ◽

Structure Investigations

The effect of both the relative magnitude of electrophilicity of metal centres and the character of a Lewis base on the molecular structure of the electron-precise [R2M(μ-O2CPh)]2-type carboxylates and their Lewis acid–base adducts [(R2M)(μ-O2CPh)(py-Me)] is reported.

Download Full-text

IR Spectrum of CH3CN−BF3in Solid Neon: Matrix Effects on the Structure of a Lewis Acid−Base Complex

The Journal of Physical Chemistry B ◽

10.1021/jp0656375 ◽

2007 ◽

Vol 111 (6) ◽

pp. 1402-1407 ◽

Cited By ~ 23

Author(s):

Audrey A. Eigner ◽

John A. Rohde ◽

Christopher C. Knutson ◽

James A. Phillips

Keyword(s):

Lewis Acid ◽

Ir Spectrum ◽

Matrix Effects ◽

Acid Base ◽

Base Complex

Download Full-text

The Number of Hydride Ions in AlH2Cl Available for Hydrogenolysis of 1,3-Dioxolanes

Canadian Journal of Chemistry ◽

10.1139/v71-352 ◽

1971 ◽

Vol 49 (12) ◽

pp. 2166-2168 ◽

Cited By ~ 7

Author(s):

H. A. Davis ◽

R. K. Brown

Keyword(s):

Lewis Acid ◽

Intermediate Compound ◽

Acid Base ◽

Base Complex ◽

Hydride Ion ◽

Hydride Ions ◽

Similar Complex

2-Methyl-1,3-dioxolane (1) in ether is hydrogenolyzed completely to 2-ethoxyethanol by an equimolar proportion of AlH2Cl, whereas a 1/2 mol of AlH2Cl hydrogenolyzes 1 mol of 1 only to the extent of 50%. In the latter case, the intermediate compound 2-ethoxyethoxyhydridoaluminum chloride (C2H5OCH2CH2OAlHCl) formed with half of the 2-methyl-1,3-dioxolane, even though it contains a hydride ion, fails to react with the remainder of the dioxolane. This is believed due to the preference of C2H5OCH2CH2OAlHCl to form an internal Lewis acid-base complex rather than form a similar complex with 1, a step essential to facilitate the hydrogenolysis of 1.

Download Full-text

Interplay of hemilability and redox activity in models of hydrogenase active sites

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1710475114 ◽

2017 ◽

Vol 114 (46) ◽

pp. E9775-E9782 ◽

Cited By ~ 27

Author(s):

Shengda Ding ◽

Pokhraj Ghosh ◽

Marcetta Y. Darensbourg ◽

Michael B. Hall

Keyword(s):

Lewis Acid ◽

Hydrogen Evolution Reaction ◽

Resting State ◽

Active Sites ◽

Reductive Elimination ◽

Lewis Base ◽

Redox Activity ◽

Production Mechanism ◽

Acid Base ◽

Redox Active

The hydrogen evolution reaction, as catalyzed by two electrocatalysts [M(N2S2)·Fe(NO)2]+, [Fe-Fe]+ (M = Fe(NO)) and [Ni-Fe]+ (M = Ni) was investigated by computational chemistry. As nominal models of hydrogenase active sites, these bimetallics feature two kinds of actor ligands: Hemilabile, MN2S2 ligands and redox-active, nitrosyl ligands, whose interplay guides the H2 production mechanism. The requisite base and metal open site are masked in the resting state but revealed within the catalytic cycle by cleavage of the MS–Fe(NO)2 bond from the hemilabile metallodithiolate ligand. Introducing two electrons and two protons to [Ni-Fe]+ produces H2 from coupling a hydride temporarily stored on Fe(NO)2 (Lewis acid) and a proton accommodated on the exposed sulfur of the MN2S2 thiolate (Lewis base). This Lewis acid–base pair is initiated and preserved by disrupting the dative donation through protonation on the thiolate or reduction on the thiolate-bound metal. Either manipulation modulates the electron density of the pair to prevent it from reestablishing the dative bond. The electron-buffering nitrosyl’s role is subtler as a bifunctional electron reservoir. With more nitrosyls as in [Fe-Fe]+, accumulated electronic space in the nitrosyls’ π*-orbitals makes reductions easier, but redirects the protonation and reduction to sites that postpone the actuation of the hemilability. Additionally, two electrons donated from two nitrosyl-buffered irons, along with two external electrons, reduce two protons into two hydrides, from which reductive elimination generates H2.

Download Full-text

Assembly of NHC-stabilized 2-hydrophosphasilenes from Si(iv) precursors: a Lewis acid–base complex

Dalton Transactions ◽

10.1039/c6dt04321f ◽

2016 ◽

Vol 45 (48) ◽

pp. 19290-19298 ◽

Cited By ~ 9

Author(s):

Debabrata Dhara ◽

Debdeep Mandal ◽

Avijit Maiti ◽

Cem B. Yildiz ◽

Pankaj Kalita ◽

...

Keyword(s):

Lewis Acid ◽

Acid Base ◽

Base Complex

Reaction of an aryldichlorosilane with lithiumarylphosphide leads to 1,2-dihydro-2-chlorophosphasilane which yields NHC-stabilized 2-hydrophosphasilene upon NHC-assisted elimination of HCl.

Download Full-text

Cleaving DNA-model phosphodiester with Lewis acid–base catalytic sites in bifunctional Zr–MOFs

Dalton Transactions ◽

10.1039/c9dt00246d ◽

2019 ◽

Vol 48 (23) ◽

pp. 8044-8048 ◽

Cited By ~ 1

Author(s):

Ying-Hua Zhou ◽

Zhiyan Zhang ◽

Margaret Patrick ◽

Fan Yang ◽

Rangling Wei ◽

...

Keyword(s):

Lewis Acid ◽

Active Sites ◽

Lewis Base ◽

Zinc Hydroxide ◽

Acid Base ◽

Enhanced Activity ◽

Nitrophenyl Phosphate ◽

Catalytic Sites ◽

Catalytic Active Sites ◽

Hydrolysis Of

UiO-67-bpydc-Zn with isolated multi-catalytic active sites was fabricated as a catalyst for the hydrolysis of bis(p-nitrophenyl) phosphate as a DNA model. The enhanced activity may likely be attributed to the cooperation effects between the Lewis acid from the zirconium center at the node and the zinc hydroxide Lewis base in the linkers.

Download Full-text