• No results found

98

assembly, which is also supported from the solid-state evidence. Furthermore, the bicarbonate dimer complex 8b shows average chemical shift of Δδ = 2.50 ppm as relatively broad -NH signals in its 1H-NMR data, but the gradual quantitative addition up to 2.0 equiv. of TEAHCO3-

solution results in severe and huge broadening of downfield shifted urea -NH protons.

Subsequently, the disappearance followed by severe broadening of both urea -NH signals of L8

upon titration with n-TBAF salts is observed due to proton abstraction. The binding constant for bicarbonate and fluoride with L8 could not be determined due to massive broadening and even vanishing of -NH signals during the titration process. The hydrated chloride complex 8d shows negligible average downfield shift (Δδ = 0.014 ppm for the -NH protons in its 1H NMR data) compared to oxyanions, indicating relatively less binding of chloride in the solution state.

Overall, the binding of a particular anion with respective receptor and the discrepancies of the binding mode in the solid and solution states are common in the literature. As in the solid state, the anion binding within the receptor cavity is stabilized by a number of non-covalent interactions; hence receptors exhibit well-organized and compact conformation with the respective anions. Meanwhile, due to the very loose orientations of the receptor and anion in solution, a different host-guest binding stoichiometry is observed in most of the cases, which is mainly governed by the weaker non-covalent interactions.

99

tetrameric cooperative barrel of both the isomeric receptors L6 and L7. Moreover, both halo- methylphenyl functionalized receptors form either fluoride or bromide trapped non-cooperative host-guest self-assembly via construction of semicircular ligand architecture. On the other hand, the bis-(trifluoromethyl)-phenyl aryl di-substituted bis-urea receptor L8 has been proved to be a decent receptor for recognition of hydrated anions in solid as well as in solution state. Receptor L8 in its neutral form and with its very highly acidic urea -NH groups effectively entrap, the asymmetrically coordinated (hydrated and naked) divalent sulfate anions, fluoride ion-induced (HCO3)2 dimer by aerial CO2 fixation, polymeric acetate-water cluster and acyclic chair-shaped unique acyclic chloride-water tetrameric guest. Hence, the results obtained from host-guest self- assemblies and calculating the terminal aryl centroid distances in each anion complex of meta- phenylenediamine based bis-urea receptors L4-L8, it is clearly concluded that the architecture and anion binding modes of particular receptor in respective anion complexes are heavily governed by either the positional isomeric variation of terminal aryl substituents or anion dimensions in case of receptors L4-L7, but the terminal aryl meta-disubstitutionin L8 become regularly accountable for the non-cooperative anion binding mode and the semi-circular architecture of receptor in its anion complexes irrespective of the guest dimensions. Overall, the report of substituent-driven systematic anion/hydrated anion binding of the potential bis-urea receptors is reliable to interpret the data and consistent to justify the variation, which would be useful to develop new categories of uncommon host-guest assemblies.

References

4.1 (a) P. A. Gale, Acc. Chem. Res., 2006, 39, 465; (b) D. A. Jose, D. K. Kumar, B. Ganguly and A. Das, Org.

Lett., 2004, 6, 3445.

4.2 (a) C. A. Ilioudis, D. A. Tocher and J. W. Steed, J. Am. Chem. Soc., 2004, 126, 12395; (b) G. W. Bates, P. A.

Gale and M. E. Light, Chem. Commun., 2007, 2121; (c) Anion Coordination Chemistry, ed. K. Bowman- James, A. Bianchi and E. Garcia-España, Wiley-VCH, New York, 2012.

4.3 (a) M. Arunachalam and P. Ghosh, Chem. Commun. 2009, 5389; (b) T. W. Hudnall, C.-W. Chiu, F. P. Gabbai, Acc. Chem. Res. 2009, 42, 388; (c)M. Arunachalam and P. Ghosh, Inorg. Chem. 2010, 49, 943.

4.4 (a) P. D. Beer, P. A. Gale and D. K. Smith, Supramolecular Chemistry; Oxford University Press: Oxford, U.K., 1999; (b) J. L. Sessler, P. A. Gale and W. S. Cho, Anion Receptor Chemistry: Monographs in Supramolecular Chemistry; RSC Publishing: Cambridge, UK, 2006.

4.5 (a) M. Zuhayra, W. U. Kampen, E. Henze, Z. Soti, L. Zsolnai, G. Huttner and F. Oberdorfer, J. Am. Chem. Soc.

2006, 128, 424; (b) B.-Q. Ma, H.-L. Sun and S. Gao, Chem. Commun. 2004, 2220; (c) M. Mascal, L. Infantes, J. Chisholm, Angew. Chem., Int. Ed. 2006, 45, 32; (d) S. O. Kang, D. Powell, V. W. Day and K. Bowman- James, Cryst. Growth Des. 2007, 7, 606; (e) M. Yoshizawa, T. Kusukawa, M. Kawano, T. Ohhara, I. Tanaka, K. Kurihara, N. Niimura and M. Fujita, J. Am. Chem. Soc. 2005, 127, 2798.

4.6 (a)H. Ohtaki, T. Radnai, Chem. Rev. 1993, 93, 1157; (b) D. T. Richens, The Chemistry of Aqua Ions; Wiley:

Chichester, 1987.

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4.7 (a) P. A. Gale, S. E. Garcıa-Garrido and J. Garric, Chem. Soc. Rev., 2008, 37, 151; (b) C. Caltagirone and P. A.

Gale, Chem. Soc. Rev., 2009, 38, 520.

4.8 (a) Cametti, M.; Rissanen, K. Chem. Commun. 2009, 2809; (b) Kang, S. O.; VanderVelde, D.; Powell, D.;

Bowman-James, K. J. Am. Chem. Soc. 2004, 126, 12272 (c)A systematic review of the efficacy and safety of fluoridation, National Health and Medical Research Council, Australian Government, 2007, available at:

http://www.nhmrc.gov.au/. (d)J. W. Pflugrath and F. A. Quiocho, Nature, 1985, 314, 257; (e) T. H. Milby and R. C. Baselt, Am. J. Ind. Med., 1999, 35, 192; (f)K. Caldeira, A. K. Jain and M. I. Hoffert, Science, 2003, 299, 2052; (g) Climate Change, 2007: Synthesis Report, International Panel on Climate Change; Cambridge University Press: Cambridge, U.K., 2007

4.9 (a) S. K. Dey, A. Basu, R. Chutia, and G. Das RSC Adv., 2016, 6, 26568; (b) R. Dutta and P. Ghosh Chem.

Commun., 2014, 50, 10538.

4.10 (a) R. Li, Y. Zhao, S. Li, P. Yang, X. Huang, X.-J. Yang and B. Wu, Inorg. Chem., 2013, 52, 5851; (b) S. J.

Brooks, P. R. Edwards, P. A. Gale and M. E. Light, New J. Chem., 2006, 30, 65; (c) L. E. Karagiannidis, C. J.

E. Haynes, K. J. Holder, I. L. Kirby, S. J. Moore, N. J. Wells and P. A. Gale, Chem. Commun., 2014, 50, 12050.

4.11 (a) U. Manna, R. Chutia, and G. Das Cryst. Growth Des. 2016, 16, 2893; (b) U. Manna, S. Kayal, S. Samanta and G. Das Dalton Trans., 2017, 46, 10374; (c) U. Manna and G. Das CrystEngComm, 2017, 19, 5622.

4.12 (a)A. Basu and G. Das, Chem. Commun., 2013, 49, 3997; (b) S. Chakraborty, R. Dutta, M. Arunachalam and P. Ghosh, Dalton Trans., 2014, 43, 2061; (c) U. Manna, S. Kayal, B. Nayak and G. Das Dalton Trans., 2017, 46, 11956

4.13 (a) T. Gunnlaugsson, P. E. Kruger, P. Jensen, F. M. Pfeffer and G. M. Hussey, Tetrahedron Lett., 2003, 44, 8909; (b) S. J. Brooks, P. A. Gale and M. E. Light, Chem. Commun., 2006, 4344; (c) I. Ravikumar and P.

Ghosh, Chem. Commun., 2010, 46, 1082; (d) S. K. Dey, R. Chutia and G. Das, Inorg. Chem., 2012, 51, 1727.

Annexure 4

Fig A4.1 2D-NOESY NMR spectra of (a) free L6 receptor and (b) isolated carbonate-(water)2-carbonate complex 6a in DMSO-d6.

101

Figure A4.2 X-ray structures (partial) depicting average terminal aryl centroid distances in (a) DMF-solvated free receptor L4, (b) DMF-solvated free receptor L5, (c) hydrated-fluoride complex 4a, (d) sulfate complex 4b, (e) acetate complex 4c, (f) hydrated-sulfate complex 5a and (g) DMSO-coordinated bromide complex 5b.

Fig A4.3 X-ray structures (partial) depicting average terminal aryl centroid distances and intra-guest distances inside tetrameric barrel (as applicable) in (a) hydrated-carbonate complex 6a, (b) double sulfate trapped complex 6b, (c) double sulfate trapped complex 7a, (d) fluoride complex 6c, (e) bromide complex 6d and (f) fluoride complex 7b.

102

Table A4.1 Crystallographic parameters and refinement details of receptors L4-L5 and theiranion complexes

Parameters L4 4a 4b 4c L5 5a 5b

Formula C26H30N8O8 C36H52FN7O7 C72H104N14O20S C38H55N7O8 C26H30N8O8 C60H48N18O29S2 C38H62BrN7O7S

Fw 582.58 713.85 1473.75 737.89 582.58 1549.28 840.91

Crystal system Monoclinic Monoclinic Monoclinic Monoclinic Monoclinic Triclinic Triclinic

Space group C 2/c P C P2 1/c P2 1/c P 21/n P -1 P -1

a/Å 27.673(3) 16.7790(13) 16.8011(7) 16.8967(11) 17.2678(11) 17.903(2) 10.8105(7) b/Å 14.7494(15) 32.2701(19) 16.5666(8) 17.0645(12) 13.2242(8) 20.595(4) 11.8310(9) c/Å 15.122(3) 15.5234(14) 15.4398(6) 15.4683(11) 25.5435(15) 23.597(3) 18.7901(17)

α/o 90.00 90.00 90.00 90.00 90.00 110.030(9) 99.875(6)

β/o 106.169(13) 105.795(9) 108.543(3) 110.564(4) 100.374(3) 111.747(7) 95.166(6)

γ/o 90.00 90.00 90.00 90.00 90.00 93.136(9) 111.252(4)

V/Å3 5928.1(15) 8087.9(11) 4074.4(3) 4175.8(5) 5737.6(6) 7426.0(2) 2176.1(3)

Z 8 8 2 4 8 2 2

Dc/g cm-3 1.306 1.173 1.185 1.174 1.349 0.693 1.283

μ Mo Kα/mm-1 0.099 0.085 0.109 0.083 0.102 0.083 1.045

T/K 298(2) 298(2) 298(2) 298(2) 298(2) 298(2) 298(2)

θ max. 19.25 12.82 23.18 21.84 20.44 15.47 24.46

Total no. of reflections 28691 42094 61251 19254 31799 75492 26172

Independent reflections 5224 41635 10223 7415 10860 25679 5773

Observed reflections 2741 29062 4870 4916 7632 14969 4529

Parameters refined 383 1854 488 483 766 970 504

R1, I > 2σ(I) 0.0854 0.1024 0.1051 0.0530 0.0655 0.1002 0.0540

wR2 (all data) 0.3099 0.3184 0.3098 0.1845 0.2058 0.1396 0.1548

GOF (F2) 1.102 1.180 1.161 1.073 1.007 0.988 1.020

CCDC No. 1450225 1450226 1450227 1450229 1450230 1450231 1450232

Table A4.2 Crystallographic parameters and refinement details of anion complexes of receptors L6-L7

Parameters 6a 6b 6c 6d 7a 7b

Formula C154H226Cl8N20O16 C76H112Cl4N10O8S C38H55Cl2FN5O2 C54H92Br2Cl2N6O2 C76H111Br4N10O8S C38H56Br2FN5O2

Fw 2893.11 1467.62 703.77 1088.04 1644.41 793.68

Crystal system monoclinic triclinic monoclinic orthorhombic triclinic orthorhombic

Space group C c P -1 P 21/n P b c a P -1 P 21 21 21

a/Å 28.888 (14) 12.812(6) 9.612(6) 15.301(5) 12.800(8) 9.595(10)

b/Å 23.264(9) 16.220(7) 19.079(19) 25.296(8) 16.278(7) 18.924(12)

c/Å 24.761(11) 21.053(9) 21.675(17) 31.713(11) 20.793(9) 22.044(17)

α/o 90.00 73.309(3) 90.00 90.00 74.842(4) 90.00

β/o 97.383(4) 83.915(3) 91.739(6) 90.00 84.573(4) 90.00

γ/o 90.00 84.668(3) 90.00 90.00 84.538(4) 90.00

V/Å3 16502.5(13) 4158.2(3) 3973.1(6) 12275.0(7) 4151.6(4) 4002.4(6)

Z 4 2 4 8 2 4

Dc/g cm-3 1.164 1.172 1.177 1.178 1.316 1.317

μ Mo Kα/mm-1 F000

0.200 6208.0

0.223 1572.0

0.206 1508.0

1.448 4624.0

2.020 1714.0

2.067 1656.0

T/K 298(2) 298(2) 298(2) 298(2) 298(2) 298(2)

θ max. 28.770 28.453 28.901 25.321 28.849 28.676

Total no. of

reflections 42484 63157 19914 96099 37580 12928

Independent

reflections 39853 19182 9752 10728 20041 9727

Observed

reflections 12984 12020 3673 5199 9516 6225

Parameters refined 1748 958 457 615 915 439

R1, I > 2σ(I) 0.1042 0.0754 0.0821 0.0593 0.0930 0.0808

wR2, I > 2σ(I) 0.2619 0.1890 0.1925 0.1537 0.1699 0.1491

GOF (F2) 0.939 0.976 1.115 1.029 1.088 0.964

CCDC No. 1536469 1536470 1536471 1536472 1536473 1536474

103

Table A4.3 Crystallographic parameters and refinement details of anion complexes of receptors L8

Parameters L8.DMF L8.DMSO 8a 8b 8c 8d

Formula C57H49F24N11O7 C28H26F12N4O4S2 C136H186F36N16O16S2 C58H88F12N6O8 C42H53F12N5O5 C40H50ClF12N5O3

Fw 1456.07 774.65 3049.13 1225.34 935.89 912.30

Crystal system monoclinic monoclinic monoclinic monoclinic monoclinic monoclinic

Space group P 21/c P 21/c P 21/c P 21/c P 21 I 2/c

a/Å 16.624(8) 17.969(15) 22.490 (8) 19.591 (19) 13.450(11) 25.970 (11)

b/Å 21.501(8) 20.983(14) 22.667(7) 22.197 (14) 8.627(15) 8.754(5)

c/Å 20.832(9) 9.532 (10) 31.102(13) 16.033(14) 20.472(2) 45.267(3)

α/o 90.00 90.00 90.00 90.00 90.00 90.00

β/o 111.63(5) 104.71(9) 96.970(3) 102.823(9) 94.730(8) 104.053(5)

γ/o 90.00 90.00 90.00 90.00 90.00 90.00

V/Å3 6922.1(6) 3476.3(5) 15738.0(10) 6798.4(10) 2367.4(5) 9983.0(10)

Z 4 4 4 4 2 8

Dc/g cm-3 1.397 1.480 1.287 1.197 1.313 1.214

μ Mo Kα/mm-1 F000

0.137 2960.0

0.256 1576.0

0.138 6392.0

0.101 2600.0

0.118 976.0

0.159 3792.0

T/K 298(2) 298(2) 298(2) 298(2) 298(2) 298(2)

θ max. 28.957 28.827 28.876 28.816 28.732 28.867

Total no. of reflections 36632 17317 71348 39758 12485 22919

Independent reflections 17117 8651 38839 16771 11419 12349

Observed reflections 5729 3326 29512 9160 7479 4724

Parameters refined 934 519 1890 764 592 654

R1, I > 2σ(I) 0.1122 0.0957 0.1072 0.1262 0.1119 0.0969

wR2, I > 2σ(I) 0.3241 0.2466 0.2547 0.2939 0.2513 0.2723

GOF (F2) 1.171 1.171 1.152 1.171 1.177 1.186

CCDC No. 1551278 1551279 1551280 1551281 1551282 1551283

Table A4.4 Details of Hydrogen Bonding contacts in receptors L4-L5 and theiranion complexes

Complex D−H∙∙∙A d(H∙∙∙A)/Å d(D∙∙∙A)/Å <D−H∙∙∙A/°

L4 N2H∙∙∙O8 2.061(3) 2.88(4) 158.6(2)

N3H∙∙∙O8 2.086(3) 2.90(4) 157.1(2)

N4H∙∙∙O7 2.130(3) 2.95(4) 157.8(2)

N5H∙∙∙O7 2.090(3) 2.90(4) 156.9(2)

4a N2H∙∙∙F1 1.881(8) 2.67(1) 152.2(7)

N3H∙∙∙F1 1.878(7) 2.68(1) 155.6(7)

N21H∙∙∙F1 1.989(9) 2.79(1) 154.6(7)

N16H∙∙∙F4 1.916(7) 2.70(1) 150.9(7)

N17H∙∙∙F4 1.856(8) 2.66(1) 155.8(7)

N4H∙∙∙F4 N10H∙∙∙F2 N22H∙∙∙F2 N23H∙∙∙F2 N8H∙∙∙F3 N9H∙∙∙F3 N15H∙∙∙F3

1.943(9) 2.052(7) 1.909(6) 1.878(6) 1.847(6) 1.899(6) 1.989(7)

2.75(2) 2.86(1) 2.69(1) 2.67(9) 2.65(1) 2.68(9) 2.83(1)

156.0(8) 156.2(7) 150.3(6) 153.1(6) 153.9(6) 150.3(6) 164.7(7)

4b N2H∙∙∙O7 2.08(1) 2.89(1) 157.3(4)

N2H∙∙∙O8 2.106(7) 2.90(9) 152.4(4)

N3H∙∙∙O7 2.308(9) 3.34(8) 151.1(4)

N3H∙∙∙O9 2.388(8) 3.11(1) 141.8(4)

N3H∙∙∙O10 1.999(8) 2.83(1) 163.4(4)

N4H∙∙∙O7 2.155(8) 2.90(9) 144.5(4)

N4H∙∙∙O9 2.137(7) 2.98 (8) 168.6(4)

N5H∙∙∙O8 2.069(6) 2.90(7) 161.7(4)

N5H∙∙∙O10 2.085(7) 2.86(8) 148.7(4)

4c N2H∙∙∙O9

N3H∙∙∙O8 N4H∙∙∙O8 N5H∙∙∙O8

1.966(6) 1.983(4) 2.015(3) 2.066(3)

2.821(9) 2.820(8) 2.836(7) 2.863(5)

173.9(4) 163.6(4) 159.4(4) 153.6(4)

L5 N2H∙∙∙O16 2.066(3) 2.878(4) 157.0(2)

N3H∙∙∙O16 2.003(2) 2.828(3) 160.5(2)

N4H∙∙∙O17 2.117(3) 2.927(4) 156.9(2)

N5H∙∙∙O17 2.082(2) 2.901(3) 158.9(2)

N8H∙∙∙O19 2.134(2) 2.937(4) 155.4(2)

N9H∙∙∙O19 2.076(3) 2.901(4) 160.4(2)

N10H∙∙∙O13 2.030(2) 2.854(4) 159.9(2)

104

N11H∙∙∙O13 2.064(3) 2.869(4) 155.7(2)

5a N2H∙∙∙O20 2.244(4) 3.082(6) 164.7(4)

N3H∙∙∙O19 1.931(6) 2.746(9) 157.8(5)

N4H∙∙∙O26 2.499(4) 3.284(8) 152.0(5)

N5H∙∙∙O26 1.986(3) 2.839(6) 170.8(5)

N8H∙∙∙O25 N9H∙∙∙O25

2.031(3) 2.237(4)

2.876(6) 3.053(6)

167.7(5) 158.4(5) N10H∙∙∙O21

N11H∙∙∙O20 N14H∙∙∙O23 N15H∙∙∙O24 N16H∙∙∙O22 N17H∙∙∙O22

2.011(4) 2.303(6) 2.211(5) 2.003(8) 2.346(6) 1.872(6)

2.868(7) 3.143(9) 3.02(1) 2.86(1) 3.101(1) 2.724(1)

174.2(5) 165.5(5) 155.7(5) 170.6(4) 147.2(5) 170.3(5)

5b N2H∙∙∙O7 1.992(3) 2.813(5) 159.6(3)

N3H∙∙∙O7 2.151(3) 2.952(5) 154.8(3)

N4H∙∙∙Br1 2.658(6) 3.480(4) 160.3(3)

N5H∙∙∙Br1 2.435(6) 3.288(4) 171.4(3)

Table A4.5 Details of Hydrogen Bonding contacts in anion complexes of receptors L6-L7

Complex D−H∙∙∙A d(D∙∙∙H)/Å d(H∙∙∙A)/Å d(D∙∙∙A)/Å <D−H∙∙∙A/° Symmetry codes

6a N1-H1N∙∙∙O10 0.86 2.09 2.905(15) 158 x,y,z

N2-H2N∙∙∙O11 0.86 1.93 2.781(15) 174 x,y,z

N4-H4N∙∙∙O14 0.86 2.06 2.894(17) 164 x,y,z

N5-H5N∙∙∙O10 0.86 2.09 2.915(15) 160 x,y,z

N6-H6N∙∙∙O9 0.86 2.08 2.932(15) 171 x,y,z

N7-H7N∙∙∙O12 0.86 2.07 2.900(16) 163 x,y,z

N8-H8N∙∙∙O12 0.86 2.21 2.981(17) 149 x,y,z

N9-H9N∙∙∙O13 0.86 2.10 2.878(18) 150 x,y,z

N10-H10N∙∙∙O14 0.86 1.93 2.790(17) 177 x,y,z

N11-H11N∙∙∙O11 0.86 2.13 2.932(15) 155 x,y,z

N12-H12N∙∙∙O11 0.86 2.06 2.860(15) 154 x,y,z

N13-H13N∙∙∙O13 0.86 2.01 2.846(18) 165 x,y,z

N14-H13P∙∙∙O12 0.86 1.95 2.806(16) 174 x,y,z

N15-H15N∙∙∙O9 0.86 2.08 2.939(15) 172 x,y,z

N16-H16N∙∙∙O10 0.86 2.23 3.048(16) 158 x,y,z

6b N1-H1N∙∙∙O7 0.83 1.99 2.803(9) 167 1-x,1-y,1-z

N2-H2N∙∙∙O9 0.87 2.11 2.972(8) 176 1-x,1-y,1-z

N3-H3N∙∙∙O5 0.91 2.03 2.893(8) 157 1+x,y,z

N4-H4N∙∙∙O5 0.86 2.51 3.217(7) 140 1+x,y,z

N4-H4N∙∙∙O8 0.86 2.24 3.057(8) 158 1+x,y,z

N5-H5N∙∙∙O8 0.86 2.13 2.923(8) 154 -x,1-y,1-z

N6-H6N∙∙∙O9 0.90 2.01 2.887(8) 166 -x,1-y,1-z

N7-H7N∙∙∙O5 0.83 2.09 2.922(8) 172 x,y,z

N8-H8N∙∙∙O7 0.84 2.02 2.851(8) 172 x,y,z

6c N1-H1N∙∙∙F1 0.86 2.04 2.825(4) 152 3/2-x,-1/2+y,1/2-z

N2-H2N∙∙∙F1 0.86 1.81 2.639(4) 162 3/2-x,-1/2+y,1/2-z

N3-H3N∙∙∙F1 0.86 1.79 2.624(4) 163 1+x,y,z

N4-H4N∙∙∙F1 0.86 2.06 2.831(4) 149 1+x,y,z

6d N4-H1∙∙∙Br1 0.86 2.49 3.318(7) 162 x,y,z

N3-H2∙∙∙Br1 0.86 2.52 3.354(6) 164 x,y,z

N2-H3A∙∙∙Br2 0.86 2.63 3.460(5) 163 -1/2+x,1/2-y,-z

N1-H4A∙∙∙Br2 0.86 2.56 3.403(5) 166 -1/2+x,1/2-y,-z

7a N1-H1N∙∙∙O8 0.86 2.19 2.986(8) 154 1-x,1-y,-z

N2-H2N∙∙∙O6 0.86 2.09 2.911(7) 160 1-x,1-y,-z

N3-H3N∙∙∙O5 0.86 2.11 2.958(8) 171 x,-1+y,z

N4-H4N∙∙∙O7 0.86 2.06 2.864(8) 156 x,-1+y,z

N5-H5N∙∙∙O7 0.86 2.04 2.819(7) 151 1-x,1-y,-z

N6-H6N∙∙∙O6 0.86 2.15 2.989(7) 165 1-x,1-y,-z

N7-H7N∙∙∙O5 0.86 2.08 2.906(7) 160 x,-1+y,z

N8-H8N∙∙∙O5 0.86 2.37 3.105(8) 144 x,-1+y,z

N8-H8N∙∙∙O8 0.86 2.36 3.151(8) 153 x,-1+y,z

7b N1-H1N∙∙∙F1 0.86 1.91 2.722(8) 156 x,y,z

N2-H2N∙∙∙F1 0.86 1.86 2.681(8) 159 x,y,z

N3-H3N∙∙∙F1 0.86 1.84 2.644(9) 156 -x,1/2+y,1/2-z

N4-H4N∙∙∙F1 0.86 2.00 2.793(9) 152 -x,1/2+y,1/2-z

105

Table A4.6 Details of Hydrogen Bonding contacts in receptors L8 and its anion complexes

Complex D−H∙∙∙A d(D∙∙∙H)/Å d(H∙∙∙A)/Å d(D∙∙∙A)/Å <D−H∙∙∙A/° Symmetry codes

L8.DMF N1-H1N∙∙∙O5 0.86 2.14 2.940(5) 156 1-x,-1/2+y,1/2-z

N2-H2N∙∙∙O5 0.86 2.03 2.843(5) 157 1-x,-1/2+y,1/2-z

N5-H5N∙∙∙O6 0.86 2.05 2.863(6) 158 1-x,1-y,1-z

N6-H6N∙∙∙O6 0.86 2.13 2.932(6) 156 1-x,1-y,1-z

N7-H7N∙∙∙O7 0.86 2.00 2.821(6) 161 x,y,z

N8-H8N∙∙∙O8 0.86 2.12 2.880(6) 146 x,y,z

L8.DMSO N1-H1N∙∙∙O4 0.86 2.07 2.883(6) 158 1-x,-y,1-z

N2-H2N∙∙∙O4 0.86 2.10 2.908(5) 157 1-x,-y,1-z

8a N1-H1N∙∙∙O10 0.86 1.97 2.817(7) 168 -1+x,y,z

N2-H2N∙∙∙O9 0.86 1.99 2.805(6) 157 -1+x,y,z

N3-H3N∙∙∙O8 0.86 2.01 2.843(6) 162 1-x,1/2+y,1/2-z

N4-H4N∙∙∙O7 0.86 1.93 2.750(6) 159 1-x,1/2+y,1/2-z

N5-H5N∙∙∙O12 0.86 2.26 3.082(8) 160 x,y,z

N5-H5N∙∙∙O13 0.86 2.57 3.277(6) 140 x,y,z

N6-H6N∙∙∙O13 0.86 2.00 2.831(6) 163 x,y,z

N7-H7N∙∙∙O8 0.86 2.05 2.842(6) 153 -1+x,y,z

N8-H8N∙∙∙O9 0.86 1.87 2.729(6) 175 -1+x,y,z

N9-H9N∙∙∙O14 0.86 1.93 2.769(7) 167 1-x,-1/2+y,1/2-z

N10-H10N∙∙∙O12 0.86 2.27 3.113(8) 166 1-x,-1/2+y,1/2-z

N11-H11N∙∙∙O11 0.86 1.99 2.845(6) 171 x,y,z

N12-H12N∙∙∙O13 0.86 2.01 2.841(6) 162 x,y,z

8b N1-H1N∙∙∙O3 0.86 1.89 2.724(5) 165 x,y,z

N2-H2N∙∙∙O4 0.86 1.95 2.802(5) 172 x,y,z

N3-H3N∙∙∙O7 0.86 1.92 2.777(5) 173 x,y,z

N4-H4N∙∙∙O6 0.86 1.92 2.767(5) 167 x,y,z

O5-H5O∙∙∙O7 0.99 1.63 2.614(7) 174 -x,1/2+y,1/2-z

O8-H8O∙∙∙O4 1.00 1.70 2.611(5) 149 -x,-1/2+y,1/2-z

8c N1-H1N∙∙∙O3 0.86 2.01 2.859(8) 169 1-x,-1/2+y,-z

N2-H2N∙∙∙O4 0.86 1.94 2.784(8) 168 1-x,-1/2+y,-z

N3-H3N∙∙∙O5 0.86 2.17 2.981(7) 157 -1+x,y,z

N4-H4N∙∙∙O5 0.86 2.00 2.832(8) 162 -1+x,y,z

8d N1-H1N∙∙∙O3A 0.86 2.24 3.059(9) 158 -x,y,1/2-z

N1-H1N∙∙∙O3B 0.86 2.37 3.173(14) 155 -x,y,1/2-z

N2-H2N∙∙∙O3A 0.86 2.45 3.231(9) 152 -x,y,1/2-z

N2-H2N∙∙∙O3B 0.86 2.18 3.023(14) 165 -x,y,1/2-z

N3-H3N∙∙∙Cl1 0.86 2.40 3.210(3) 158 x,y,z

N4-H4N∙∙∙Cl1 0.86 2.31 3.119(3) 157 x,y,z

106

para-Phenylenediamine based isomeric neutral

scaffolds: Evidence of cyclic (HCO

3

)

2

-dimer and