(1‐Adamantyl)methyl Glycidyl Ether: A Versatile Building Block for Living Polymerization

(1‐Adamantyl)methyl glycidyl ether (AdaGE) is introduced as a versatile monomer for oxyanionic polymerization, enabling controlled incorporation of adamantyl moieties in aliphatic polyethers. Via copolymerization with ethoxyethyl glycidyl ether (EEGE) and subsequent cleavage of the acetal protection groups of EEGE, hydrophilic linear polyglycerols with an adjustable amount of pendant adamantyl moieties are obtained. The adamantyl unit permits control over thermal properties and solubility profile of these polymers (LCST). Additionally, AdaGE is utilized as a termination agent in carbanionic polymerization, affording adamantyl‐terminated polymers. Using these structures as macroinitiators for the polymerization of ethylene oxide affords amphiphilic, in‐chain adamantyl‐functionalized block copolymers.

     

New pH sensitive network: Combination of an amphiphilic degradable polyester with a β-cyclodextrin copolymer

A novel hydrophobic monomer, ethyladamantyl malolactonate, has been synthesized and copolymerized with benzyl malolactonate by anionic ring-opening polymerization. The ratio of adamantyl monomer varied from 0 to 100 mol%. Deprotection of benzyl groups leads to a water soluble copolyester with carboxylic acid lateral functions which give a polyelectrolyte character to the corresponding polymers. The mixture of a copolyester containing 10% of adamantyl groups and a β-cyclodextrin/epichlorohydrin copolymer in aqueous solution leads to a new pH-dependant associating system. The solution behavior of this system was studied by viscosimetry as a function of pH, concentration and ratio of both copolymers. At the initial solution pH (pH=2), the copolyester adopts a coiled structure as a result of hydrophobic interactions between the pendant adamantyl groups. Consequently, no network formation is observed as shown by a very low viscosity. As the pH increase, the viscosity of the medium increases and reaches a maximum at pH=5. At this pH, the copolyester expands because of electrostatic repulsions between the carboxylate pendant functions. Consequently, the adamantyl groups are accessible and can be encapsulated into the β-cyclodextrin cavities resulting in a significant increase of the viscosity.     

Synthesis of poly(vinyl ether)‐based,ABA triblock‐type thermoplastic elastomers with functionalized soft segments and their gas permeability

The ABA‐type triblock copolymers consisting of poly(2‐adamantyl vinyl ether) [poly(2‐AdVE)] as outer hard segments and poly(6‐acetoxyhexyl vinyl ether) [poly(AcHVE)], poly(6‐hydroxyhexyl vinyl ether) [poly(HHVE)], or poly(2‐(2‐methoxyethoxy)ethyl vinyl ether) [poly(MOEOVE)] as inner soft segments were synthesized by sequential living cationic polymerization. Despite the presence of polar functional groups such as ester, hydroxyl, and oxyethylene units in their soft segments, the block copolymers formed elastomeric films. The thermal and mechanical properties and morphology of the block copolymers showed that the two polymer segments of these triblock copolymers were segregated into microphase‐separated structure. Effect of the functional groups in the soft segments on gas permeability was investigated as one of the characteristics of the new functional thermoplastic elastomers composed solely of poly(vinyl ether) backbones. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1114–1124     

Synthesis of ABA‐triblock and star‐diblock copolymers with poly(2‐adamantyl vinyl ether) and poly(n‐butyl vinyl ether) segments: New thermoplastic elastomers composed solely of poly(vinyl ether) backbones

ABA‐type triblock copolymers and AB‐type star diblock copolymers with poly(2‐adamantyl vinyl ether) [poly(2‐AdVE)] hard outer segments and poly(n‐butyl vinyl ether) [poly(NBVE)] soft inner segments were synthesized by sequential living cationic copolymerization. Although both the two polymer segments were composed solely of poly(vinyl ether) backbones and hydrocarbon side chains, they were segregated into microphase‐separated structure, so that the block copolymers formed thermoplastic elastomers. Both the ABA‐type triblock copolymers and the AB‐type star diblock copolymers exhibited rubber elasticity over wide temperature range. For example, the ABA‐type triblock copolymers showed rubber elasticity from about ?53 °C to about 165 °C and the AB‐type star diblock copolymer did from about ?47 °C to 183 °C with a similar composition of poly(2‐AdVE) and poly(NBVE) segments in the dynamic mechanical analysis. The AB‐type star diblock copolymers exhibited higher tensile strength and elongation at break than the ABA‐type triblock copolymers. The thermal decomposition temperatures of both the block copolymers were as high as 321–331 °C, indicating their high thermal stability. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Electrochemical gene detection based on supramolecular complex formation by ferrocenyl-β-cyclodextrin and adamantylnaphthalene diimide bound to double stranded DNA

Adamantylnaphthalene diimide 1 was synthesized as a highly selective double stranded DNA (dsDNA) binding reagent. The binding studies with sonicated calf thymus DNA as a model of dsDNA revealed that 1 can bind to dsDNA by the threading mode, where the two adamantyl moieties are located in the major and minor grooves of dsDNA separately and the complex of 1 with DNA duplex was stabilized by capping of the adamantyl moieties of 1 bound to dsDNA by β-cyclodextrin. The adamantyl moieties of 1 could be incorporated also into the cavity of ferrocenyl-β-cyclodextrin (Fc-β-CD), resulting in the formation of a supramolecular complex. When this complex is formed on the DNA probe-immobilized electrode, electrochemical DNA detection was feasible: the electrode hybridized with target DNA gave rise to a current peak corresponding to the ferrocene oxidation upon treatment with 1 and Fc-β-CD.     

Synthesis of statistical and block copolymers containing adamantyl and norbornyl moieties by reversible addition‐fragmentation chain transfer polymerization

The synthesis of statistical and block copolymers, consisting of monomers often used as resist materials in photolithography, using reversible addition‐fragmentation chain transfer (RAFT) polymerization is reported. Methacrylate and acrylate monomers with norbornyl and adamantyl moieties were polymerized using both dithioester and trithiocarbonate RAFT agents. Block copolymers containing such monomers were made with poly(methyl acrylate) and polystyrene macro‐RAFT agents. In addition to have the ability to control molecular weight, polydispersity, and allow block copolymer formation, the polymers made via RAFT polymerization required end‐group removal to avoid complications during the photolithography. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 943–951, 2010     

Adamantyl ferrocene derivatives: Antioxidant abilities and effects on model lipid membranes

A series of homoannularly and heteroannularly substituted adamantyl ferrocene derivatives has been synthesized and their effects on membrane fluidity were investigated using liposomes as the membrane models. The liposome formulations of adamantyl ferrocene derivatives were characterized by using dynamic light scattering, differential scanning calorimetry and fluorescence anisotropy measurements. It was demonstrated that adamantyl ferrocene derivatives incorporated into the liposome significantly affect the structure of the lipid bilayer. The results of the study have revealed that adamantyl ferrocene derivatives, compounds 9 – 12, partition into the hydrophobic/hydrophilic interface of the membrane, causing a significant decrease in membrane fluidity. The antioxidant potential of synthesized compounds was assessed with DPPH method and it was shown that the examined compounds possess certain antioxidant activity.     

Synthesis and characterization of physical crosslinking systems based on cyclodextrin inclusion/host‐guest complexation

New supramolecular assemblies based on cyclodextrin and adamantane were prepared. Two methacrylate monomers bearing cyclodextrin and adamantane were synthesized, and copolymerized with poly(ethylene glycol) methyl ether methacrylate, (PEGMA, 300 g/mol), by free radical polymerization. Copolymers bearing pendent cyclodextrin and adamantane were characterized by NMR, FTIR, TGA, SEC, Differential scanning calorimetry (DSC), and UV‐visible spectrophotometer. All copolymers showed two distinct glass transitions. The specific interaction between pendent adamantyl and cyclodextrin was examined by ¹H‐NMR. The viscoelastic properties of supramolecular assemblies were investigated with frequency and temperature sweep experiments. The specific host‐guest interaction between pendent adamantyl and cyclodextrin lead to large increases of the viscosity; and depending on the concentration of these groups, also to gel formation. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 581–592, 2010     

Synthesis of Narrow Molecular Weight Distribution Copolymers for ArF Photoresist Materials by Nitroxide Mediated Polymerization

ArF candidate photoresist polymers have been synthesized by nitroxide mediated polymerization (NMP). Statistical copolymerizations of α‐gamma butyrolactone methacrylate, 3‐hydroxy‐1‐adamantyl methacrylate, and 2‐methyl 2‐adamantyl methacrylate with 5–10 mol% of controlling comonomers (i.e., styrene, p‐acetoxystyrene, 2‐vinyl naphthalene, acrylonitrile, and pentafluorostyrene), which are necessary for controlled polymerization of methacrylates by NMP with the unimolecular alkoxyamine initiator BlocBuilder, have been used. As little as 5 mol% controlling comonomer in the feed is demonstrated to be sufficient to produce linear evolution of number average molecular weight against conversion (X) up to X = 0.7 for relatively low target degrees of polymerization. All of the resulting copolymers have relatively low dispersities and show relatively low absorbance at 193 nm, comparable to other 193 nm candidate photoresists reported previously, with the exception of VN‐containing copolymer.

     

Synthesis and thermal,optical, and mechanical properties of sequence‐controlled poly(1‐adamantyl acrylate)‐block‐poly(n‐butyl acrylate) containing polar side group

We prepared the sequence‐controlled block copolymers including poly(1‐adamantyl acrylate) (PAdA) and poly(n‐butyl acrylate) sequences as the hard and soft segments, respectively, by the organotellurium‐mediated living radical polymerization. The thermal, optical, and mechanical properties of the adamantane‐containing block copolymers with polar 2‐hydroxyethyl acrylate (HEA) and acrylic acid (AA) repeating units were investigated. The microphase‐separated structures of the block copolymers were confirmed by the differential scanning calorimetry and atomic force microscopy observations as well as dynamic mechanical measurements. The α‐ and β‐dispersions due to the main‐chain and side group molecular motions, respectively, of the hard and soft segments were observed. Their transition temperatures and activation energies increased due to the formation of intermolecular hydrogen bonding by the introduction of the HEA and AA repeating units. The effects of the hydrogen bonding on their tensile elasticity, strength, and strain were also evaluated. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2899–2910     

A new reagent for incorporating the 2‐(1‐adamantyl)‐2‐propyloxycarbonyl protecting group into amines

A new reagent to incorporate the 2‐(1‐adamantyl)‐2‐propyloxycarbonyl (Ad‐POC) protecting group into amines, 2‐(1‐adamantyl)‐2‐propyl p‐nitrophenylcarbonate, was prepared in two steps from the commercially available 1‐adamantylcarbonyl chloride. The Ad‐POC group was introduced into a variety of amines and amino acid derivatives. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:192–195, 2000     

Surface plasmon resonance study of the interaction of a beta-cyclodextrin polymer and hydrophobically modified poly(N-isopropylacrylamide)

Surface plasmon resonance (SPR) technique is used to follow, both in real time and in situ, the association between a physically adsorbed polymer of beta-cyclodextrin (pbetaCD) and different hydrophobically modified poly(N-isopropylacrylamide) (PNIPAM) copolymers containing either adamantyl or dodecyl groups. This association is due to the complex formation between the hydrophobic groups and the betaCD cavities. Therefore, the adsorbed amount of PNIPAM onto the pbetaCD layer depends on the substituent and on its substitution level. The association and dissociation rate constants are evaluated from the kinetics of PNIPAM adsorption. An estimation of the association constants leads to values higher than 10(4) M(-1), reflecting the strong interaction between these polymers.     

Increasing Complexity in Adamantyl Thioethers Characterized by Rotational Spectroscopy

We report on the synthesis and characterization using high-resolution rotational spectroscopy of three bulky thioethers that feature an adamantyl group connected to a sulfur atom. Detailed experimental and theoretical structures are provided and compared with the 1,1′-diadamantyl ether. In addition, we expand on previous findings concerning microsolvation of adamantyl derivatives by investigating the cluster formation between these thioethers and a water molecule. The investigation of such clusters provides valuable insights into the sulfur-centered hydrogen bonding in thioethers with increasing size and steric repulsion.     

Synthesis of two-coordinate iron aryloxides and their reactions with organic azide: Intramolecular C-H bond amination

The synthesis and reaction of homoleptic iron(II) complexes with 2,6-di-adamantyl-substituted aryloxides [OC₆H₂-2,6-Ad-4-R]⁻ ([OAr^AdR]⁻, Ad = adamantyl, R = Me, ⁱPr) are described. Monomeric two-coordinate iron aryloxides Fe(OAr^AdR)₂ (R = Me, 1; ⁱPr, 2) were synthesized by the reaction of Fe[N(SiMe₃)₂]₂ with 2 equiv of HOAr^AdR. Treatment of 1 and 2 with 1-azidoadamantane resulted in intramolecular insertion of an adamantyl nitrene into a methylene C-H bond of the aryloxide adamantyl substituent, yielding the corresponding amine-aryloxide complexes Fe(OAr^AdR)(OAr^AdR-NHAd) (R = Me, 3; ⁱPr, 4). Molecular structures of all these complexes are reported.     

Synthesis of <Emphasis Type="Italic">N</Emphasis>-vinylpyrrolidone copolymers with 2-aminoethyl methacrylate as drug carriers

Radical copolymerization of N-vinylpyrrolidone and 2-aminoethyl methacrylate hydrochloride has been studied. Molecular and hydrodynamic characteristics of the resulting copolymers have been determined, and their structure has been confirmed. Conditions favoring conversion of these copolymers into copolymers of N-vinylpyrrolidone with 2-aminoethyl methacrylate of different composition have been elucidated. The suitability of the prepared copolymers as polymeric carriers of monofluoroquinolone ofloxacin has been demonstrated.     

Full Characterization and some reactions of 1‐(2‐adamantyl)‐3‐(1‐adamantyl)aziridin‐2‐one

We found that 1‐(2‐adamantyl)‐3‐tert‐butylaziridin‐2‐one ( 5a ) is unstable. It slowly decomposes at room temperature, although detectable by IR spectroscopy (1840 cm^?1 band in CCl₄). On the other hand, a closely related analogue, 1‐(2‐adamantyl)‐3‐(1‐adamantyl)aziridin‐2‐one ( 5b ), is very stable, in concurrence with an earlier report [1]. We fully characterized aziridinone 5b , identified its thermal decomposition products ( 7 and 8 ) and reacted it with two aprotic ionic (tBuO^? and HO^?) and one protic non‐ionic nucleophile (benzylamine). All three products ( 9b , 10 , and 11 ) result from exclusive cleavage of the lactam (1‐2) bond.     

High temperature resistant tailor‐made poly(meth)acrylates bearing adamantyl group via atom transfer radical polymerization

This investigation reports preparation of tailor‐made poly(meth)acrylates bearing adamantyl group using atom transfer radical homo and copolymerization via initiator as well as via monomer approach. The ATRP of methyl methacrylate was investigated using different initiators having adamantyl group (like AdMBr or AdBr) as well as conventional EBiB initiator and CuBr as catalyst in combination with PMDETA as ligand. It was observed that the incorporation of the bulky adamantyl group increased the rate of polymerization. The polymerization proceeded through first‐order kinetics and molecular weights increased linearly with conversion, close to the targeted molecular weights. The living nature of the end‐group was confirmed by MALDI‐TOF‐mass spectrometry and chain extension experiment. The homopolymerization of adamantyl methyl acrylate (AdMA) and its copolymerization with MA was successfully carried out using methylbromopropionate (MBrP) as initiator and CuBr/dNbpy as the catalyst. Interestingly, the resultant poly(meth)acrylates bearing the adamantyl group had excellent thermal stability and much better thermal stability than the similar polymers without adamantyl group as evidenced from thermogravimetry analysis (TGA) and isothermal TGA studies. Importantly, incorporation of adamantyl group “adamantly” increases rate of polymerization, thermal stability, and glass transition temperature of the polymers. All the polymers were characterized by NMR, MALDI‐TOF‐MS, DSC, and TGA analysis. © Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7101–7113, 2008     

Guest recognition with micelle-bound cavitands

We report that a benzimidazole cavitand is incorporated in aqueous phosphocholine (PC) micelles, folds into the vase conformation, and functions as small-molecule host. As a micelle-bound host it has the ability to sequester selective hydrophobic guest "anchors" into its interior. These anchors include cycloalkanes, adamantanes, and nitrogen heterocycles that compete favorably with the large excess of PC alkyl side-chains that make up the micelle interior. The adamantyl anchor was further functionalized with a fluorophore, and in another instance a dipeptide and both guests retain their recognition properties with the micelle-bound cavitand. Additionally, we report that variations in the cavitand periphery and rim are well-tolerated under our experimental conditions. We find that enhanced binding toward certain guests in both micelles as well as in solution occurs in response to titration with base; this previously unknown property of benzimidazole cavitands is reported in detail.     

Synthesis and Properties of Carbocyclic Schiff Bases

New Schiff bases containing both adamantyl and phenyl fragments in a single molecule were synthesized by condensation of appropriate diamines with aromatic aldehydes. The condensation products were brought into reduction and nucleophilic addition reactions.     

Synthesis and study of the inhibitory activity of adamantylphosphates with respect to <Emphasis Type="Italic">Myo</Emphasis>-inositolmonophosphatase

The paper presents the synthesis of a series of adamantyl phosphate esters. Five compounds (oxo and hydroxy substituted adamantyl phosphates) were tested for their inhibitory activity with respect to myo-inositol monophosphatase.