ライフサイエンスコーパス: crown ether

1 polyether ligands: L(C) (cryptand) and L(E) (crown-ethers).

2 t inhibit binding of the ammonium ion to the crown ether.

3 e hydrogen bond acceptor oxygen atoms in the crown ether.

4 ation of a stable host-guest system with the crown ether.

5 e 1,2-bis(benzimidazole)ethane motif for the crown ether.

6 ring a rhodol chromophore linked with an aza-crown ether.

7 strates, including biotin, chromophores, and crown ethers.

8 ether bridges, as well as benzimidazolidine crown ethers.

9 is of the known complexation behavior of the crown ethers.

10 ng capacity that is >/=18 times that of thio-crown ethers.

11 med by studying alkali metal ion coordinated crown ethers.

12 that of complexes between metal cations and crown ethers.

13 st paper describing his synthesis of over 50 crown ethers.

14 e sensor molecules based on N-methylbenzoaza-crown ethers.

15 tions in a manner similar to that found with crown ethers.

16 columnar self-assembly of triarylamines and crown-ethers.

17 tion of the sodium cation by the polydentate crown ether 12-crown-4.

18 A series of crown ethers, 12-crown-4, 15-crown-5, 18-crown-6, and di

19 duce the extent of compound fragmentation, a crown ether, 18-crown-6, was added postcolumn to the sys

20 Binding constants of several crown ether-alkali metal cation complexes that were prev

21 Experiments with crown ether-alkali metal complexes confirm the validity

22 nt" binding involving axial coordination and crown ether-alkyl ammonium cation complexation to form t

23 own-8) esters derived from the hydroxymethyl crown ether and aliphatic diacid chlorides (CxC, x = num

24 g; and (iii) host-guest interactions between crown ether and dialkylammonium substrates.

25 sol-gel, and silica sol-gel impregnated with crown ether and with active carbon, were deposited on th

26 ccupy guest positions in bimetallic, inverse crown ethers and C(4) fragments ultimately appear in bim

27 ed receptors, including, but not limited to, crown ethers and cryptands, is responsible for the very

28 he hydrogen bonding interactions between the crown ethers and ferrioxamine B.

29 d others), organic ligands (O- and N-donors, crown ethers and related molecules, MALDI matrix molecul

30 interaction modes: hydrogen bonding between crown ethers and thioureas and the halogen bonding betwe

31 vy metal binding selectivities of five caged crown ethers and two polyether reference compounds in me

32 eir diprotonated form in the presence of the crown ether, and both nitrogen atoms appear to associate

33 Crown ethers are an important family of compounds that a

34 Crown ethers are at their most basic level rings constru

35 However, crown ethers are typically highly flexible, frustrating

36 Thus, crown ethers are useful in modeling the size-selective b

37 raphiles are synthetic ion channels that use crown ethers as entry portals and that span phospholipid

38 Since their discovery, crown ethers as well as the most recent carbon nanostruc

39 containing oligomeric ether units (including crown ethers) attached to the arylsulfonyl ring in the o

40 A crown ether based charge reduction approach was applied

41 ppropriate divalent as well as a luminescent crown ether based host 1 and paraquat derivatives, 2(PF(

42 tely 19 A (the maximum distance spanning the crown ether binding sites in PBC).

43 compounds, which were used to represent the crown-ether blocking group and the axle of a rotaxane.

44 Since the accidental discovery of the crown ethers by Pedersen half a century ago, the chemist

45 In the electrically neutral crown ether (C2H4O)6, six ethylene oxide monomers are li

46 scribed, based on a highly sodium-selective, crown ether-capped calix[4]arene ionophore, capable of r

47 istry and were prominent in the discovery of crown ethers, carcerands and catenanes.

48 The KF/crown ethers catalytic systems proved to be highly effic

49 used in synergistic combination with a model crown ether cation host was shown to have a strong effec

50 Cyclodextrins/aromatic rods, crown ethers/cationic rods and pillararenes/alkyl chains

51 se protein ions by noncovalent attachment of crown ethers (CEs).

52 s from the immobilization of the Pb2+ by the crown ether chelating groups.

53 Two crown ether chemosensors featuring a boron azadipyrrin c

54 The abilities of the crown ether clusters to complex with these monovalent li

55 When the cationic Sr-crown ether complex is created in a two-phase water-RTIL

56 When a Sr(NO(3))(2)-crown ether complex is directly dissolved in a water-sat

57 The general applicability of this crown ether complexation approach to clinical samples wa

58 he presence of poorly resolved conformers of crown ether complexes and peptides leading to more accur

59 water-RTIL system, however, only cationic Sr-crown ether complexes are observed in the RTIL phase.

60 The Sr(II)-crown ether complexes formed in a room-temperature ionic

61 r the activation of laser-desorbed metal ion-crown ether complexes was examined.

62 ubstituents to allow their interactions with crown ether compounds to be probed by (19)F NMR spectros

63 lysine substitution(s) in neutral synthetic crown ether containing 14-mer peptide affect the peptide

64 acceptor [2]catenane, which is composed of a crown ether containing a hydroquinone unit and a 1,5-dia

65 A crown ether-containing macrobicycle was used as the whee

66 saturated RTIL, both nitrate ligands and the crown ether coordinate the Sr, as observed in a conventi

67 ed by binding positively charged ions to the crown ether core, highlighting the potential for applica

68 of complexes of polyether ligands including crown ethers, cryptands, glycols, glymes, and related po

69 rotaxanes that utilize both metal-ligand and crown ether-dialkylammonium noncovalent interactions are

70 ds was compared with those of the monovalent crown ethers dibenzo[24]crown-8 and benzometaphenylene[2

71 The derived crown ether diol 1d was converted to pyridyl cryptand 12

72 at the triaroylbenzene-derived bis- and tris-crown ethers do not engage in intramolecular chelation o

73 of the same basic structures of the original crown ethers embedded in graphene.

74 on group that binds the analyte selectively (crown ethers for metal ions), or a molecular-recognition

75 d selectivities of these monoaza-substituted crown ethers for Na(+), K(+), Cs(+), and Sr(2+) were stu

76 ion motif, in which boronic acid and PEG (or crown ether) functional groups are prepositioned in a ph

77 both redox-active ferrocenyl and host-guest crown ether functionalities has been achieved via coordi

78 trol over positioning of either ferrocene or crown ether functionalities.

79 ontrolled by thermal, pH (i-motif), K(+) ion/crown ether (G-quadruplexes), chemical (pH-doped polyani

80 d on paraquats or viologens (G(2+)2X(-)) and crown ethers (H).

81 nding abilities of these mono- and polytopic crown ethers have been probed through picrate extraction

82 Eleven anthracylmethyl crown ethers have been synthesized and evaluated as fluo

83 stems (dimers 3 and 4) endowed with suitable crown ethers have been synthesized as receptors for a fu

84 al 1:2 complexation between an electron-rich crown ether host and electron-deficient naphthalene diim

85 viologen residue in these dendrimers and the crown ether host bis-p-phenylene-34-crown-8 were also in

86 n of 1:1 and 1:2 complexes of a fluorophilic crown ether in fluorous ISE membranes and how this resul

87 By using 5 mM crown ether in the organic phase and 10 mM CsNO3 with 0.

88 rees unidirectional rotation of up to 87% of crown ethers in a [2]catenane rotary motor.

89 Crown ethers in graphene offer a simple environment that

90 These monoaza-substituted crown ethers in ionic liquids were investigated as recyc

91 d 1D ensemble was used to order the appended crown ethers in such a way that they roughly stack on to

92 from Pedersen's ground-breaking discovery of crown ethers in the mid-1960s.

93 comprising a polymerizable ammonium salt and crown ether, in combination with dynamic ADMet polymeriz

94 ors for Na+ and K+ have been fabricated from crown ethers incorporated into polymeric hydrogels.

95 based, first, on the complementary ammonium-crown ether interaction and, second, on the pi-pi intera

96 ionalized fullerene, crown-C60, via ammonium-crown ether interactions to yield SWNT/Pyr-NH3+/crown-C6

97 d viologen unit assembles with a 24-membered crown ether into a stable host-guest complex displaying

98 olyfluorene grafted with a K(+)-intercalated crown ether involving six oxygen atoms (PFCn6:K(+)) for

99 Cross sections for the series of crown ether ions and complexes that are observed are rep

100 The crown ether is a useful chiral discriminating agent for

101 In this approach, a crown ether is added to a solution containing a mixture

102 The crown ether is designed to act as a host toward biologic

103 ee cationic guest species, G(+), by the host crown ether is independent of counterion.

104 oefficient for Pb(2+) into a control gel (no crown ether), K(p), is 1.00 +/- 0.018 (errors reported a

105 The pincer-crown ether ligand exhibits tridentate, tetradentate, an

106 ated in a pentadentate fashion by the pincer-crown ether ligand.

107 al cation binding with a macrocyclic "pincer-crown ether" ligand.

108 ectrometry carried out on solutions of these crown ether-like bridges confirmed that Li+, Na+, and K+

109 four monomers coordinate a single K(+) in a crown-ether-like structure, with, on average, 1.5 cation

110 Association of the ammonium ion with the crown ether likely involves two hydrogen bonds with the

111 nkers are [2]rotaxanes with varying sizes of crown ether macrocycles ([22]crown-6, 22C6; [24]crown-6,

112 tinguishable host-guest interactions between crown ether macrocycles and ammonium with different size

113 Since the discovery of crown ethers, macrocycles have been recognized as powerf

114 The host-guest recognition properties of the crown ether moieties and their ability to complex cation

115 ecule is detrimental to the abilities of the crown ether moieties to complex with monovalent dialkyla

116 bonds between the terminal NH3(+) groups and crown ether moieties was detected in MeCN solutions.

117 Introduction of a crown ether moiety allows changing the photoreaction par

118 caffold with a flexible, weakly donating aza-crown ether moiety are reported.

119 etween the two aromatic units of each folded crown ether moiety in 1.

120 Recognition of Na+ by the crown ether moiety in CE-bpy results in a significant in

121 ino acid promoter (L-Ala), that binds to the crown ether moiety of 1 via electrostatic interactions,

122 organoplatinum(II) acceptor decorated with a crown ether moiety that provide the basis for self-assem

123 pe-persistent monomer, containing a flexible crown ether moiety, gives an initial Archimedean-based c

124 nitrogen atoms appear to associate with the crown ether moiety.

125 oidal array (PCCA) hydrogel which contains a crown ether molecular recognition group.

126 ilities than the naked peptide ions, and the crown ether molecules appear to interact specifically wi

127 tudies of aromatic ions and protonated amine/crown ether noncovalent complexes generated via ion/mole

128 These agents, dubbed crown ether nucleophilic catalysts (CENCs), are 18-crown

129 fulvalene unit in a mechanically interlocked crown ether occupies the cavity of a cyclobis(paraquat-p

130 Triarylamine molecules appended with crown-ethers or carboxylic moieties form self-assembled

131 likely involves two hydrogen bonds with the crown ether oxygen atoms and an ion pair with the carbox

132 They are homologues of dibenzo crown ether phase-transfer catalysts and were prepared f

133 spacer to an electron donor and a H-bonding crown ether polycycle.

134 Dibenzotetraaza (DBTA) crown ethers possess two o-phenylenediamine moieties.

135 ng of Na(+)-ions to the highly selective aza-crown ether receptor due to reduction of the photoinduce

136 logous chromoionophores based on N-phenylaza-crown ethers regarding both the ionochromism and the cat

137 ycol) diacids gives macrocycles analogous to crown ethers, representing minimal examples of out-of-eq

138 in which a 1,5-dioxynaphthalene unit in the crown ether resides inside the cavity of the tetracation

139 on of external K with 15 mM of 18-Crown-6 (a crown ether) restored inactivation even in the absence o

140 h the metal cation located in the receptor's crown ether ring and the trigonal oxyanion hydrogen bond

141 remote recognition site for the interlocked crown ether ring through electrochemical stimulation.

142 ic sensors feature either 18- or 27-membered crown ether rings and have been evaluated as visible sen

143 When the crown ether rings are 14-crown-4, 15-crown-5, and 18-cro

144 Symmetrical tris(crown ether)s possessing three benzo(15-crown-5) or thre

145 imized film compositions containing 50 mol % crown ether showed substantial responses (< or = 200 nm)

146 r-none response, as the vast majority of the crown ether sites must be occupied with a promoter for a

147 R, we determined that binding to the 4 or 16 crown ether sites occurred in an anti-cooperative fashio

148 form a 3-imino-1-oxoisoindoline derivatized crown ether species.

149 is seen in the case of a previously reported crown ether "strapped" calixarene-calixpyrrole ion-pair

150 itions where a Cs(+) cation was bound to the crown ether-strapped calix[4]arene subunit.

151 systems based on ammonioalkyl derivatives of crown ether styryl dyes.

152 e with paraquat, 9000 times greater than the crown ether system.

153 ion and solid states even in the presence of crown ethers that compete for Li(+) coordination.

154 ound Pb2+ ions have a slow off rate from the crown ether, the bound Pb2+ PCCA diffraction transiently

155 sly developed templated syntheses of dibenzo crown ethers, this protocol makes powerful cryptand host

156 ses in aqueous solution, ranging from simple crown ether to complex enzyme-ligand interactions.

157 e actuated by the binding of the Pb2+ to the crown ether to immobilize the Pb2+ counterions.

158 tonated by the carboxylic acid groups of the crown ether to produce the corresponding ammonium and ca

159 This arrangement constrains the crown ethers to be rigid and planar.

160 nstances, it was found that clustering seven crown ethers together into one molecule is detrimental t

161 Tested on a set comprising two crown ethers, two thioureas and five halogen bond donors

162 spherical Keplerate-type capsules having 20 crown-ether-type pores and tunable internal functionalit

163 forward method for assembling multiple benzo(crown ether) units around 1,3,5-triaroylbenzene scaffold

164 A flexible, pyridine-functionalized diaza-crown ether was self-assembled into discrete supramolecu

165 ing of an ibuprofen unit connected to a half crown ether, was added to the verbenoxy-COT(2)(-),M(+)(2

166 N-Aryl-aza-crown ethers were efficiently prepared by reaction of an

167 N-Aryl-aza-crown ethers were produced in 75-91% yields.

168 sters of a homologous series of hydroxyether crown ethers were synthesized and copolymerized with hyd

169 um cations, comparable to those reported for crown ethers, were observed for an alternated N-benzylgl

170 niversary of Charles Pedersen's discovery of crown ethers, what is widely considered the birth of sup

171 e axle with a 1,10-phenanthroline containing crown ether wheel.

172 t work investigates this strategy in alkynyl crown ethers, where propargylic C-O bonds contained with

173 e efficiently prepared by reaction of an aza-crown ether with an aryl bromide via a palladium-catalyz

174 In this paper, we have designed a new crown ether with four hydroxyl groups strategically posi

175 two bistable [2]catenanes--one containing a crown ether with tetrathiafulvalene and dioxynaphthalene

176 d between secondary dialkylammonium ions and crown ethers with a [25]crown-8 constitution, however, r

177 Sterically congested o-terphenyl crown ethers with alkoxy substituents at the 2,3,4-posit

178 Reaction of the DBTA crown ethers with alkyl and benzyl halides was found to

179 red benzimidizoles were used to produce DBTA crown ethers with modified substituents and ether bridge

180 N-Aryl-aza-crown ethers with o-aryl substituents can also be synthe

181 to be a convenient route to a new family of crown ethers with overall yields of up to 48% based on t

182 1:1 and 1:2 complexes with the fluorophilic crown ether, with cumulative formation constants of up t

183 l that the self-assemblies incorporating the crown ethers work as single channels for the selective t