nmr study of 9-(1-adamantylaminomethyl)-9,10-dihydroanthracene and its β-cyclodextrin complexes

MAGNETIC RESONANCE IN CHEMISTRYMagn. Reson. Chem. 2000; 38: 925–931

NMR study of 9-(1-adamantylaminomethyl)-9,10-dihydroanthracene and its b-cyclodextrin complexes

Marta Sanchez, Teodor Parella, Enric Cervello, Carlos Jaime and Albert Virgili∗

Departament de Quımica, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona, Spain

Received 7 February 2000; revised 8 May 2000; accepted 14 May 2000

ABSTRACT: 9-(1-Adamantylaminomethyl)-9,10-dihydroanthracene was prepared via condensation of adamantylnitrilewith the 9-anthryllithium and its hydride reduction. An NMR study confirmed a boat conformation for the centralring, with the substituent of C-9 in a pseudo-axial position. The ˇ-cyclodextrin host–guest complexes of the titlecompound and of the intermediate imine were studied from three points of view: the modification of chemical shift,the intermolecular NOE and the diffusion coefficients, all of which showed different behaviour. 1-Adamantylaminewas used as a model to study the formation of the complex. Copyright 2000 John Wiley & Sons, Ltd.

KEYWORDS: NMR; 1H NMR; anthracene; adamantyl; cyclodextrin; diffusion

INTRODUCTION

The study of isolated enantiomers always consists in (apartfrom the determination of the specific rotation and thecircular dicroism) the formation of systems presenting dif-ferent properties, that is, systems with some stability thatcan be considered, at least during a certain time, diastere-omeric. Methods based on the formation of derivatives byreaction with chiral agents give rise to diastereoisomers ifthe reagent is enantiomerically pure.

Nowadays, the analysis of the enantiomers is doneby forming labile diastereomeric complexes or associa-tions. These complexes should have certain kinetic andthermodynamic stability and at the same time be in equi-librium with the isolated species. The forces responsiblefor these associations are known as weak bonds. Amongthem we find classical and non-classical hydrogen bonds,host–guest interactions and �–� stacking. These are thebases of the analysis of enantiomeric mixtures by additionof chiral solvating agents (ChSA).1 Chiral chromatogra-phy ([gas and high-performance liquid chromatography(HPLC)])2 is also based on this phenomenon. In this case,the reagent is an optically pure compound linked to thestationary phase. In fact, HPLC has been shown to be oneof the most efficient techniques for the separation of enan-tiomers, and many chiral stationary phases come from orhave been previously studied as ChSA.

Recently we reported3 the preparation of both enan-tiomers of 9-(1-amino-2,2-dimethylpropyl)-9,10-dihydro-anthracene and their behaviour as chiral solvating agents.These compounds showed a large capacity to induce chi-rality in racemic mixtures.

* Correspondence to: A. Virgili, Departament de Quımica, UniversitatAutonoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.Contract/grant sponsor : DGICYT; Contract/grant numbers: PB95-0636, PB96-1181.

Assuming that the volume of the substituents has astrong influence4 on the activity as a ChSA, we prepared9-(1-adamantylaminomethyl)-9,10-dihydroanthracene (1)by reduction of 1-adamanthyl-9-anthrylmethylimine (2).Compound 1 should have a rigid structure and conse-quently the associative complexes should be less depen-dent on the conformational equilibrium.

The adamantane group has the proper size to be intro-duced into the cavity of ˇ-cyclodextrin (ˇ-CD).5 Theformation of an inclusion complex with a CD makes itpossible to obtain an aqueous solution of a compound withsome ChSA properties.6 Some complexes of adamantanederivatives with ˛-CD,7 ˇ-CD7a,b,d – g,8 and �-CD7f,8a havebeen described, but the behaviour of the adamantylmethy-lamino radical towards ˇ-CD is unknown. The study of thehost–guest complex of 1 with ˇ-CD was carried out aftera careful analysis of that for 1-adamantylmethylamine (3)as a model.

In addition to examining these complexes by classicalNMR, we determined the diffusion rate using PGSE(pulse gradient spin-echo) methods.9 The diffusion of acompound is proportional to the molecular size,10 andin the case of complexes of CD it is similar to thatof cycloamylose,11 but different from that of the guestcompound. We can measure the diffusion coefficient (D)of a compound by monitoring the intensity (Ai) of aproton NMR signal with respect to the intensity of theapplied gradient (g). From Eqn (1) (where υ is the gradientduration and is the diffusion time),

ln

(Ag

A0

)D ��2g2υ2� � υ/3�D �1�

we can calculate this parameter for the protons of theguest, which, if the complex corresponds to an innercomplex, should have changed to a diffusion coefficientsimilar to that of the CD.

Copyright 2000 John Wiley & Sons, Ltd. Magn. Reson. Chem. 2000; 38: 925–931

926 M. SANCHEZ ET AL.

RESULTS AND DISCUSSION

Synthesis and structure

Racemic 9-(1-adamantylaminomethyl)-9,10-dihydroanth-racene (1) was obtained by reducing 1-adamanthyl-9-anthrylmethylimine (2), which in turn was prepared bycondensation of bromoanthracene with 1-cyanoadaman-tane (Scheme 1).

Scheme 1. Preparation of 1.

The yield of the complete process was 82%. Asdescribed3 for the tert-butyl derivative, the central ringis reduced before the imino group. This is shown afterquenching the process at short reaction times, when9-(1-adamanthylaminomethyl)-9,10-dihydroanthracene isfound. Other chemical and electrochemical reductivemethods were tried in order to avoid the hydrogenationof the central ring, and the results were always similar(unpublished results). Finally, the compound was savedas its hydrochloride derivative.

The structural study of 1 includes the conformationalanalysis of the central ring and the measurement of thedynamic barrier of rotation of the C-9, 11 bond. Two boatconformations of the central ring are possible, with H-9 ina pseudo-equatorial or pseudo-axial position (Scheme 2).

We assume that in the first conformation, where thesubstituent is in a pseudo-axial position, the C-9, 11 bondcan rotate with no steric hindrance whereas in the secondconformation the same rotation could be of higher energyowing to the proximity to protons H-1 and H-8. An NOEexperiment (Fig. 1) with saturation of H-9 results in anincrement of the magnetization of protons H-1 and H-8 butnot of H-10. In the same way, irradiation of H-10 affordsNOE on H-11 but not on H-9; this is only compatible withthe first conformation of the molecule 1. No saturationtransfer is produced.

Scheme 2. Conformational equilibrium of 1.

The torsional energy surface for the rotation around theC-9,11 bond has been studied by molecular mechanicscalculations. The C-8,9,11,N and the C-9,11,N,H dihedralangles were driven from C180° to �180° in 10° stepsusing the standard two-bond drive implemented in theMM3 force field.12 Analysis of the results shows that theconformational equilibrium of 1 is represented by threerotamers, A, B and C (Scheme 3), with relative popula-tions of 64, 12 and 24%, respectively, with a very lowrotational barrier around the C-9,11 bond [3.9 kcal mol�1)�1 kcal D 4.184 kJ)]. Considering the important contribu-tion of conformer C, one can assign the signals of H-1and H-11 after the NOE observed (only on H-8) whenH-11 was saturated.

b-Cylodextrin complexes

Because of the structural complexity of 1 and the lack ofthe studies on host–guest complexes of adamantylamine(Scheme 4) derivatives, we studied the adamantylmethy-lamine 3 as a model. The inclusion complex was studiedfrom three points of view: the modification of chemicalshift,13 the intermolecular NOE and the diffusion coeffi-cients.

The 1H NMR spectra of the complex of 3 with ˇ-CDat several guest/host ratios are presented in Fig. 2. Onlythe inner protons H-3 and H-5 of the carbohydrate areshifted to higher field, while the aliphatic guest protonsare deshielded. At the highest values of the guest/hostratio, when the adamantane compound is in great excess,the chemical shifts return to the original values. Usu-ally, equilibrium constants are deduced from analysis ofthe variation of chemical shifts from individual protons.14

Nevertheless, different values are deduced when usingdifferent protons. To avoid this point, we developed acomputer program (CALCK) which accounts for the con-tribution of all protons at the same time.15 The equilibriumconstant was deduced to be K D 149 š 18 M�1.

Considering the low solubility of the complexes, Job’smethod16 could not be applied and the stoichiometry of the


NMR OF 9-(1-ADAMANTYLAMINOMETHYL)-9,10-DIHYDROANTHRACENE AND CD COMPLEXES 927

Figure 1. (A) 1H NMR spectrum of 1. NOE spectra of 1 after saturation of (B) H-9 and (C) H-11.

Scheme 3. Rotational conformers of 1.

complex was calculated using the concentration method13

taking the anomeric proton H-1 as a reference. Plotting υagainst the guest/host ratio �r� for the host protons [or vsthe host/guest ratio �r 0� for the guest protons], we obtain,for each proton, two straight lines (Fig. 3) that allow us

Scheme 4

to conclude that the ratio of 3 to ˇ-CD in the complexis 1 : 1.

The formation of an inclusion complex was proved intwo ways, the presence of intermolecular NOE (obtainedas ROE using modified DPFGSE sequence,17 see exp.section) and by measurements of the diffusion rate byPGSE methods.18 All protons of the adamantane partshowed NOE with the inner proton H-30 (and also, toa lesser extent, with H-50), but no intermolecular NOE is



Figure 2. 1H NMR spectra of host–guest complexes (in several ratios) of 3 and ˇ-CD.

Figure 3. Variation of the chemical shift for protons of thecomplexes of ˇ-CD and 3 at several molar ratios. (A) Forthe ˇ-CD protons; (B) for the guest protons.

observed if the ˛-aminomethylene protons are saturated.Scheme 5 represents these data.

By comparing the intensities of the signals of protonsversus the intensity of the magnetic field gradient weobtained the diffusion coefficient of each proton of ˇ-CD, 1-adamantylmethylamine and the complex obtained�host/guest D 0.78�. The average results are summarizedin Table 1, and the change in value of D of 3 in aqueoussolution and in the complex confirms the formation of theinclusion compound.

The formation of an inclusion complex between 3 andˇ-CD was simulated by MM calculations. The guest andhost were initially located far away from each other andthe guest was forced to include the host through its widerentrance by successively changing its coordinates (seeRef. 5a for a fuller explanation of the method).

To account for bimodal complexations, four differentorientations for the guest were examined. Two of them

Scheme 5. (A) Proposed and (B) calculated distribution ofthe host–guest complex of 3 in ˇ-CD.

Table 1. Diffusion coefficients (D) of host and guestmolecules (solvent D2O, 298 K)

Dhost Dguest

Compound (10�5 cm2 s�1) (10�5 cm2 s�1)

ˇ-Cyclodextrin 0.32 š 0.03 —1-Adamantylmethylamine (3) — 0.84 š 0.02Complex 3 C ˇ-CD �r D 1.6� 0.40 š 0.03 0.42 š 0.02Complex 1 C ˇ-CD �r D 0.7� 0.31 š 0.02 0.33 š 0.02Complex 2 C ˇ-CD �r D 0.7� 0.31 š 0.02 0.32 š 0.02

consider a ‘vertical’ approach: first entering the aminogroup or first entering the adamantyl group; the othertwo consider a ‘horizontal’ approach of the guest, andthe different orientation of the amino group (up or down)defines these orientations.

All of these inclusions were examined computationallyand several energy minima were obtained (usually more



than one for each inclusion); the lest stable was only8 kcal mol�1 higher in energy than the most stable. Thereare two more energy minima at 1.8 and 3.3 kcal mol�1,above the most stable one. The most stable structurecontains the adamantyl group totally included in the ˇ-CDcavity, and no hydrogen bond between the amino groupof the guest and no hydroxyl group of the host has beendetected [Scheme 5(B)].

Owing to the low solubility of 1, it was not possi-ble to obtain its 1H NMR spectrum in D2O, or that ofthe hydrochloride derivative. However, the latter salt wasdissolved in water in the presence of ˇ-CD, forming thecorresponding host–guest complex. Moreover, a compari-son of the relative displacement (at higher field) of internalprotons with the ratio of the components of the host–guestcomplex (r or r 0) showed that the complex is producedbetween two molecules of ˇ-CD and one molecule of thesalt of 1.

The NOE confirms the internal association since whenwe saturated H-3 of the adamantyl radical we observedNOE on H-30 and H-50 of ˇ-CD.

The diffusion studies led to similar conclusions to thosereached for 3. The diffusion coefficients of the protonsof ˇ-CD and those of 1 in the complex �guest/host D0.70� are similar (Table 1), confirming the formation ofthe inclusion complex. Evidently, any external associatewould be so feeble that it would move as an internal1 : 1 complex. Only in this case was a mass spectrum[matrix-assisted laser desorption/ionization time-of-flightmass spectrometry (MALDI-TOFMS) system with veryspecific conditions of the matrix, laser, etc.] obtainedthat represents the molecular weight of the 1 : 1 complex�m/z D 1480�.

Finally, the inclusion of the hydrochloride salt of 2 inˇ-CD was studied. A very different behaviour from that of

Figure 4. Variation of the chemical shift for protons of thecomplexes of ˇ-CD and 1 (hydrochloride salt) at severalmolar ratios. (A) For the ˇ-CD protons; (B) for the guestprotons.

Figure 5. Variation of the chemical shift for protons of thecomplexes of ˇ-CD and 2 at several molar ratios. (A) Forthe ˇ-CD protons; (B) for the guest protons.

1 was found. Both the shielding of the internal protons ofˇ-CD and the NOE indicated that the host–guest complexhad been formed, but the plots (Fig. 5) of the variationof the absorption with the host/guest ratio verify thearrangement of a 1 : 1 complex. The diffusion coefficientsalso correspond to the host–guest compound (Table 1).

These results indicate that the 2 : 1 stoichiometry forthe complex is achieved only when the guest presents afolded structure as in the case of 1. In this case, twomolecules of ˇ-CD form the macrostructure. However,when the molecule is planar (as in the case of 2), onlyone host is around the guest.

EXPERIMENTAL

Compounds

9-(1-Adamantyliminomethyl)anthracene (2). A solution (1.6 M) ofbutyllithium in hexane (7.3 ml, 11.68 mmol) was slowly added to adiethyl ether (40 ml) solution of 9-bromoanthracene (2 g, 7.78 mmol)kept under N2 with continuous stirring. The reaction was completedafter 2 h, and a diethyl ether solution of 9-anthracenecarbonitrile (1.88 g,11.68 mmol) was added at room temperature. After 3 h, the reaction wasquenched and the organic layer was separated, dried and concentrated.The solid residue was purified by column chromatography on silica gel[hexane–dichloromethane (1 : 4 v/v]: yellow needles (76% yield), m.p.168–170 °C; IR (KBr) (cm�1), 3240, 3050, 2903, 2846, 1602 (C N),1447, 1307, 1117, 878, 836, 730. C25H25N calc. C, 88.45; H, 7.42; N,4.13; found C, 88.46; H, 7.47; N, 4.07%. 1H NMR (CDCl3) (ppm): 1.63(s, H-13, 6H), 1.95 (s, H-14, H-15, 9H), 7.44 (m, H-2, H-3, H-6, H-7,4H), 7.87 (m, H-1, H-8, 2H), 7.94 (m, H-4, H-5, 2H), 8.40 (s, H-10),9.8 (broad, NH). 13C NMR (CDCl3) (ppm): 28.50 (C-14), 36.41 (C-15),40.93 (C-13), 43.24 (C-12), 125.23 (C-3, C-6), 125.53 (C-2, 7), 126.65(C-1, 8), 126.78 (C-10), 128.02 (C-8a, C-9a), 128.45 (C-4, C-5), 131.11(C-4a, C-10a), 160.26 (C-9), 190.53 (C-11). MS, m/z (%): 339 (15), 204(100), 177 (10), 135 (5), 79 (7), 41 (4).

9-(1-Adamantylaminomethyl)-9,10-dihydroanthracene (1). A di-ethyl ether solution (10 ml) of 9-(1-adamantyliminomethyl)anthracene(2) (200 mg, 0.59 mmol) was slowly added to a diethyl ether (10 ml)solution of LiAlH4 (447 mg, 11.8 mmol) kept under N2 with continuousstirring and with the temperature kept at 40 °C. After 30 h, reductionwas complete. The reaction was quenched and the organic layer wasseparated, dried and concentrated. The oil obtained was purified bytransformation to its hydrochloride (50% yield), m.p. 234–236 °C;IR (KBr) (cm�1), 3450, 3261, 2910, 2854, 1588, 1490, 1448, 1082,759, 737, 447. 1H NMR (DMSO) (ppm): 1.50 (m, H-13, H-15),1.83 (s, H-14), 3.05 [d, H-11, J�A,B� D 6.16 Hz), 3.92 (d, H-10eq,



J�A,B� D 18.8 Hz), 4.67 (d, H-9, J�A,B� D 6.16 Hz), 4.18 (d, H-10ax,J�A,B� D 18.8 Hz), 7.25 (m, H-2, H-3, H- 6, H- 7), 7.35 (m, H-4, H-5),7.50 (m, H-8), 7.52 (m, H-1), 7.69 (broad, NH3

C). 13C NMR (DMSO)(ppm): 27.73 (C-14), 35.52 (C-13 or C-15), 36.02 (C-10), 36.61 (C-12),37.63 (C-15 or C-13), 46.02 (C-9), 63.55 (C-11), 126.23 (C-2 or C-7),126.58 (C-7 or C-2), 127.12 (C-3 or C-6), 127.22 (C-6 or C-3), 128.32(C-4 or C-5), 128.60 (C-5 or C-4), 129.18 (C-1 or C-8), 129.26 (C-8 orC-1), 137.10 (C-4a or C-10a), 137.50 (C-10a or C-4a), 138.04 (C-8a orC-9a), 138.17 (C-9a or C-8a).

Spectra

Preparation and studies by NMR of the host–guestcomplexes. For each complex we prepared 10 sampleswith increasing guest/host ratio. For each one, variousvolumes of a solution of ˇ-CD �1.6 ð 10�5 M) were mixedwith calculated amounts of the guest in such a way thatthe volume and the total number of moles was constant.The concentration, depending on the solubility of eachguest, was measured by integration of the correspondingsignal of the 1H NMR spectra.

NMR experiments. All NMR experiments were per-formed at 300 K on a Bruker ARX400 spectrometer oper-ating at 400.16 and 100.3 MHz for the 1H and 13C nucleus,respectively, and equipped with a conventional 5 mminverse broadband probehead incorporating a z-gradientcoil and with two independent channels (1H and X).CDCl3 and D2O were used as solvents and the sampletemperature was maintained at 300 K. All the steady-stateNOE experiments were performed using low-power pre-saturation for 8 s; two dummy scans were used. The ROEexperiments on cyclodextrin complexes were performedon degassed samples using the DPFG-ROE19 sequencewith a 700 ms mixing time.

Diffusion coefficients were obtained using an LEDsequence modified18 by the use of bipolar gradients. Thediffusion measured on one proton was calculated, obtain-ing the intensity �Ag� of the signal of this nucleus atvarious gradient values. The plot of ln�Ag/A0� against

Table 2. Values of g, B, Ag and ln�A/A0) (see text)

Expt No. g(gauss cm�1) B Ag ln�A/A0�

1 0.5 59 5.635 0.00002 1.25 367 5.39 �0.04453 2.5 1470 5.349 �0.05214 3.75 3306 5.252 �0.07045 5 5879 5.217 �0.07716 6.25 9185 5.252 �0.07047 7.5 13181 4.967 �0.12628 8.75 18004 4.768 �0.16719 10 23516 4.347 �0.2595

10 11.25 29762 4.369 �0.254511 12.5 36744 4.126 �0.311712 13.75 44460 3.622 �0.442013 15 52911 3.356 �0.518214 17.5 72018 3.075 �0.605715 20 94064 2.575 �0.783116 22.5 119050 2.095 �0.989417 25 146976 1.554 �1.288218 30 211645 0.903 �1.8310

Figure 6. Plot of the variation of the intensity [ln�Ag/A0�]of the signal of H-1 of 3 against B�D �2g2υ2�4 � υ�].

B D �2g2υ2�4 � υ� gives a straight line with a slope cor-responding to the diffusion coefficient D. The final valuefor a molecule is the arithmetic mean of the values foundfor each proton. As an example, Table 2 and Fig. 6 cor-respond to the experimental values found for H-1 of asaturated solution (D2O) of 3.

MALDI-TOFMS. ToF mass spectra of the ˇ-CD com-plexes were obtained on a Bruker Biflex spectrometer witha nitrogen pulse laser (337 nm), detecting positive ions andusing an accelerating voltage of 19 kV. An aqueous solu-tion of 2,5-dihydrobenzoic acid (10 mg ml�1 O) was usedas a matrix.

MM calculations. Calculations were carried out on aVAX-6640 computer at the Computing Centre of theUAB. Allinger’s MM3(92) force field was used through-out. Phenyl rings were treated as a delocalized systemusing the standard MM3 procedures. All computationswere carried out assuming a vacuum.

Acknowledgements

Financial support was obtained from DGICYT (projects PB95-0636 andPB96-1181). The UAB is gratefully acknowledged for fellowships (E.C.and M.S.). We thank the Servei de Ressonancia Magnetica Nuclear ofthe UAB for allocating spectrometer time.

REFERENCES

1. (a) Pirkle WH, Hoover DJ. Top. Stereochem. 1982; 13: 263;(b) Weisman GR. Asymmetric Synthesis, vol. 1. Academic Press:New York, 1983; Chapt. 8; (c) Parker D. Chem. Rev. 1991; 91:1441.

2. (a) Pirkle WH, Pochapsky TC. Chem. Rev. 1989; 89: 347; (b) WelchCJ. J. Chromatogr. A 1994; 666: 3; (c) Pirkle WH, Pochapsky TC.Chem. Rev. 1989; 89: 347.

3. Port A, Virgili A, Jaime C. Tetrahedron: Asymmetry 1996; 7:1995.

4. (a) Moragas M, Cervello E, Jaime C, Virgili A, Ancian B. J.Org. Chem. 1998; 63: 8689; (b) Almer S, Virgili A. Tetrahedron:Asymmetry 1999; 10: 3719.

5. (a) Jaime C, Redondo J, Sanchez-Ferrando F, Virgili A. J. Org.Chem. 1990; 55: 4773; (b) Jaime C, Redondo J, Sanchez-Ferrando F,Virgili A. J. Mol. Struct. 1991; 248: 317; (c) Sanchez-Ruiz X,Alvarez-Larena A, Jaime C, Piniella JF, Redondo J, Virgili A,Sanchez-Ferrando F, Germain G, Baert F. Supramol. Chem. 1999;10: 219.

6. D’Souza VT, Lipkowitz KB (guest editors). Chem. Rev. 1998; 98:1741.

7. (a) Harrison JC, Eftink MR. Biopolymers 1982; 21: 1153; (b) Komi-yama M, Bender ML. J. Am. Chem. Soc. 1978; 100: 2259;(c) Gelb RI, Schwartz LM, Lauferl DA. Bioorg. Chem. 1980; 9: 450;(d) Eftink MR, Andy ML, Bystrom K, Perlmutter HD, Kristol DS.



J. Am. Chem. Soc. 1989; 111: 6765; (e) Rudiger V, Eliseev A,Simova S, Schneider HJ, Blandamer MJ, Cullis PM, Meyer AJ.J. Chem. Soc., Perkin Trans. 2 1996; 2119; (f) Cromwell WC,Bystrom K, Eftink MR. J. Phys. Chem. 1985; 89: 326; (g) Gelg RI,Schwartz LM, Laufer DA. J. Chem. Soc., Perkin Trans. 2 1984;15.

8. (a) Gelb RI, Raso S, Alper JS. Supramol. Chem. 1995; 4: 279;(b) Weickenmeter M, Wenz G. Macromol. Rapid Commun. 1996;17: 731; (c) Briggner LE, Ni XR, Tempesti F, Wadso I. Thermochim.Acta 1986; 109: 139; (d) Godınez LA, Schwartz LM, Criss CM,Kaifer AE. J. Phys. Chem. B 1997; 101: 3376; (e) Zhang B,Breslow R. J. Am. Chem. Soc. 1993; 115: 9353; (f) Gelb RI,Schwartz LM. J. Inclusion Phenom. 1989; 7: 537.

9. (a) Stilbs P. Prog. Nucl. Magn. Reson. Spectrosc. 1987; 19: 1;(b) Price WS. Annu. Rep. NMR Spectrosc. 1996; (c) Johnson CS Jr.Prog. Nucl. Magn. Reson. Spectrosc. 1999; 34: 203.

10. Gafni A, Cohen Y. J. Org. Chem. 1997; 62: 120.

11. Lin M, Jayawickrama DA, Rose RA, Delvico JA, Larive CK. Anal.Chim. Acta 1995; 307: 445.

12. Allinger NL, Yuh YH, Lii JH. J. Am. Chem. Soc. 1989; 111: 8551.13. De Fontaine DL, Ross DK, Ternal B. J. Phys. Chem. 1977; 81: 792.14. (a) Hynes MJ. J. Chem. Soc., Dalton Trans. 1993; 311; (b) Bar-

rans RE, Dougherty DA. Supramol. Chem. 1994; 4: 121; (c) Con-nors KA. Binding Constants: the Measurement of Moleular ComplexStability. John Wiley & Sons: New York, 1987.

15. Salvatierra D, Diez C, Jaime C. J. Inclusion Phenom. 1997; 27:215.

16. (a) Job P. C.R. Acad. Sci. 1925; 180: 928; (b) Sahai R, Loper GL,Lin SH, Eyring H. Proc. Natl. Acad. Sci. USA 1974; 71: 1499.

17. Stott K, Stonehouse J, Keeler J, Hwang TL, Shaka AJ. J. Am. Chem.Soc. 1995; 117: 4199.

18. Wu D, Chen A, Johnson CS Jr. J. Magn. Reson. A 1995; 115: 260.19. Adell P, Parella T, Sanchez-Ferrando F, Virgili A. J. Magn. Reson.

B 1995; 108: 77.


nmr study of 9-(1-adamantylaminomethyl)-9,10-dihydroanthracene and its β-cyclodextrin complexes

Documents