Synthesis of Diamondoid Carboxylic Acids

Abstract

Procedures for the synthesis of apical mono-, di-, and tricarboxylic acids of triamantane, [121]tetramantane, and [1(2,3)4]pentamantane, apical diacetic acids of diamantane and triamantane, as well as medial propionic acids of diamantane and triamantane were elaborated starting from the corresponding alcohols and bromides. The obtained diamondoid acids were characterized as their methyl ester derivatives. Diamondoids (nanodiamonds), which belong to a group of nanoscale carbon materials, are cage hydrocarbons with structures resembling the diamond lattice. 1 Adamantane (1), diamantane (2), and triamantane (3) belong to the lower diamondoids; the higher diamondoids, such as tetramantane (4) and pentamantane (5) show isomerism ( Figure 1). 2 Extensive studies of these hydrocarbons have been facilitated only recently after sizable amounts of diamondoids were found in oil, and by their successful isolation and isomer separation from deep natural gas condensates. 3 Adamantane (1), the first member of the diamondoid family, has been broadly studied and has found many practical applications. 4 The efficiency of adamantane amino derivatives as antiviral agents and for the treatment of diseases of the central nervous system has been well recognized. 5 The extraordinary physical and chemical properties of diamondoids, such as low surface energies, high densities as well as hydrophobicities, thermal stabilities, and resistance to oxidation, 1,6 paved the way for the use of 1 and 2, which are the most accessible and readily synthesized diamondoids, also in polymer chemistry. 7As nanometer-sized building blocks (0.5-2 nm) that can be selectively functionalized both at their periphery (CH bond substitutions) 8-10 and internally (by replacing the methylene groups with heteroatoms), 11 diamondoids possess unique properties with high potential value for nanotechnology. For instance, diamondoid thiols selfassembled on gold and silver metal surfaces are highly ordered 12 and display pronounced electron emission properties (NEA, negative electron affinity), providing a source of nearly monochromatic photoemitted electrons. 13 This makes them promising candidates for electron emission devices and in field-emission displays as well as in electron microscopes. 14 Suitably designed diamondoid derivatives have also been suggested for use in molecularscale electronics such as unimolecular rectifiers, where electron acceptors are covalently attached to functionalized diamondoids. Figure 1 Adamantane (1), diamantane (2), triamantane (3), [121]tetramantane (4), and [1(2,3)4]pentamantane (5) To make possible the selective derivatization of diamondoids and to develop applications that benefit from the attractive properties of these novel nanomaterials, the choice of functional groups is essential. For instance, in the area of metal-organic frameworks (MOFs) the first examples of hybrid inorganic-organic materials comprising diamondoids as rigid organic building blocks were presented recently. 15 Because diamondoids have welldefined three-dimen...

Evidence of Diamond Nanowires Formed inside Carbon Nanotubes from Diamantane Dicarboxylic Acid

“…Herein, we present theoretical and experimental evidence for the feasibility of a fusion reaction of diamondoid derivatives containing relatively reactive functional groups, diamantane‐4,9‐dicarboxylic acid ( 1 ),14 to 1D diamond nanowires inside CNTs. The bisapical diamondoid diacid is more reactive than the pristine diamondoid, requiring milder reaction conditions.…”

Incorporating Diamondoids as Electrolyte Additive in the Sodium Metal Anode to Mitigate Dendrite Growth

“…Diamantane‐4,9‐dicarboxylic acid (2.76 g, 10.0 mmol), SOCl 2 (16.31 g, 10 mL, 137.1 mmol), dimethylformamide (0.28 g, 0.30 mL, 3.9 mmol), and dry benzene (60 mL) were stirred and heated to reflux for 1 h. Upon cooling to room temperature, the solvent and excess SOCl 2 were evaporated to form a light‐orange residue. The residue was dissolved in dry benzene (30 mL) and the solvent was again evaporated.…”

Effects of molecular structures of carbon-based molecules on bio-lubrication

“…Four types of carbon-based molecules were investigated: phloroglucinol (phl), 1,2-dihydroxynaphthalene (dhn), diamantane-4,9-dicarboxylic acid (4,9D) [36], and graphene oxide (GO). Figure 1 shows the structures of phl, dhn, and 4,9D.…”

“…Like graphene, underivatized diamantane is strongly hydrophobic and aggregations in aqueous solutions [35]. Accordingly, the more hydrophilic derivative, diamantane-4,9-dicarboxylic acid (4,9D) [36] was applied in these studies.…”