Supplementary Information

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1 Electronic Supplementary Information for Dalton Transactions Insights into the Binding Properties of a Cuprous Ion Embedded in the Tren Cap of a Calix[6]arene and Supramolecular Trapping of an Intermediate. Guillaume Izzet,a Marie Noëlle Rager,b Olivia Reinaud.a* Supplementary Information Figure S1. Top: ESI mass (top, MeCN) and IR (bottom, nujol) spectra of complex 2. S1

2 S2

3 S3

4 Figure S2. Temperature dependence of the 1 H NMR spectra of a CD 2 Cl 2 solution of 2. a) [2]=10-2 M, [EtCN]= 0.38 M (corresponding to Fig. 4 in the text). b) [2]=10-2 M, [EtCN]= 0.14 M. S4

5 The comparative values for RCN coordinated to various calix[6]arene-based complexes clearly indicate that a slight variation of the RCN guest positioning due to the different nitrogenous arms capping the small rim accounts at the most for a 0.1 ppm variation in the chemical shift of the α- protons of the coordinated guest: [calix[6]trencu(i)rcn] + : δ(ch 3 CN) = 1.29 and δ(ch 3 CH 2 CN) = 0.75 ppm (major species) [calix[6]trenzn(ii)rcn] 2+ : δ(ch 3 CN) = 1.11 ppm and δ(ch 3 CH 2 CN) = 0.87 ppm 17 [calix[6]tris-pyridinecu(i)rcn] + : δ(ch 3 CN) = 1.16 and δ(ch 3 CH 2 CN) = 0.83 ppm; 8b [calix[6]tmpacu(i)rcn] + : δ(ch 3 CN) = 1.03 ppm (G. Izzet, PhD thesis of Paris 5 univ., 2004) [calix[6]pn 3 Cu(I)RCN] + : δ(ch 3 CN) = 1.15 ppm (G. Izzet, PhD thesis of Paris 5 univ., 2004) In strong contrast, for the minor species described in this article, we measured: [calix[6]trencu(i)rcn] + : δ(ch 3 CN) = 1.95 and δ(ch 3 CH 2 CN) = 1.30 ppm (minor species). These values are ca ppm higher field shifted if compared to the above-mentioned classical coordinated guest in various calix6arene-based complexes. Data for the thermodynamics measurements and calculation of the thermodynamics parameters. MeCN. The thermodynamic parameters for the coordination of CD 3 CN by 2 were obtained by considering that at any temperature the chemical shift δ i of each group (tbu and H Ar ) is the result of the weighted average between the chemical shift of the two forms of 2 (Equation 1a). δi = x δi, 3 + ( 1 x) δi, 2. CD CN δi δi, x = δi, 2. CD3CN δi, [ 2.CD3CN] with x = [2.CD3CN] + [ ] Equation 1a Equation 1b We considered then that for each form (2.CD 3 CN and 2. ) the chemical shift of tbu and H Ar group were independent of the temperature (the validity of this statement has been checked with other calix-based complexes that does not undergo conformational change in the same range of T). The coordination constant K can be written according to Equation 2. K [ 2.CD CN = ] [ ] x δi δi, = = 1 x δi, 2. CD3CN δi 3 2. Equation 2 The thermodynamic parameters were then extrapolated by fitting δ i as the following function: S5

6 δi δi (T) = + K(T) δi 1+ K(T),, 2. CD3CN Equation 3 Best fits (see Figure S3) were obtained with the following parameters: ΔH o = 30 kj.mol -1 ΔS o = 105 J.K -1 mol -1 δ δ δ δ = 6.54 ppm δ = 7.37 ppm ArH1, 2. CD3CN ArH1, = 7.48 ppm δ = 6.74 ppm ArH2, 2. CD3CN ArH2, = 0.68 ppm δ = 1.40 ppm tbu1, 2. CD3CN tbu1, = 1.42 ppm δ = 0.91 ppm tbu2, 2. CD3CN tbu2, Figure S4. Temperature dependence of the 1 H chemical shifts (250 MHz) of tbu and H Ar groups in 2 in CD 3 CN. EtCN. The binding constants K /c and K nc/c were obtained by direct integration of the resonances of bound and unbound EtCN in the NMR spectrum. Two experiments were carried out with the same concentration of complex ([2] 0 = 10-2 M) and different concentrations of guest {[EtCN] = 0.38 M and 0.14 M}. K /c and K nc/c were calculated in both experiments for each temperature according equations 4a and 4b. S6

7 [ 2.EtCNc] K /c(t) = [ EtCNout][ ] K nc/c [ 2.EtCNc] (T) = [ 2 EtCNnc] Equation 4a Equation 4b S7

8 Values of the molar equivalents of nitrilo guest relative to the calixarene core measured by 1 H NMR spectroscopy for the experiments reported in Fig. S2 and 4: [EtCN] 0 = 0.38 M 10 C : EtCNfree : 37.4 ± 0.5 eq EtCN c : 0.22 ± 0.02 ECN nc : / K /c (10 C) = 0.75 ± C : EtCNfree : 37.3 ± 0.5 eq EtCN c : 0.33 ± 0.02 ECN nc : / K /c (0 C) = 1.3± C : EtCNfree : 37.0 ± 0.5 eq EtCN c : 0.53 ± 0.03 ECN nc : 0.09 ± 0.01 K /c (-10 C) = 3.8 ± 1 K nc/c (-10 C) =5.9 ± 2-20 C : EtCNfree : 36.8 ± 0.5 eq EtCN c : 0.67 ± 0.03 ECN nc : 0.12 ± 0.01 K /c (-20 C) = 8.7 ± 3 K nc/c (-20 C) =5.6 ± 2-30 C : EtCNfree : 36.7 ± 0.5 eq EtCN c : 0.79 ± 0.03 ECN nc : 0.11 ± 0.01 K /c (-30 C) = 22 ± 6 K nc/c (-30 C) =7.2 ± 2-40 C : EtCNfree : 36.6 ± 0.5 eq EtCN c : 0.87 ± 0.03 ECN nc : 0.09 ± 0.01 K /c (-40 C) = 59 ± 20 K nc/c (-40 C) =9.7 ± 2-50 C : EtCNfree : 36.6 ± 0.5 eq EtCN c : 0.92 ± 0.03 ECN nc : 0.06 ± 0.01 K /c (-50 C) = 130 ± 60 K nc/c (-50 C) =15.3 ± 3-60 C : EtCNfree : 36.6 ± 0.5 eq EtCN c : 0.96 ± 0.03 ECN nc : 0.04 ± 0.01 K nc/c (-60 C) = 24 ± 10 [EtCN] 0 = 0.14 M 0 C : EtCNfree : 13.6 ± 0.3 eq EtCN c : 0.18 ± 0.02 ECN nc : / K /c (0 C) = 1.6 ± C : EtCNfree : 13.5 ± 0.3 eq EtCN c : 0.47 ± 0.02 ECN nc : / K /c (-10 C) = 3.3 ± C : EtCNfree : 13.3 ± 0.3 eq EtCN c : 0.47 ± 0.02 ECN nc : 0.05 ± 0.01 K /c (-20 C) = 7.4 ± 1 K nc/c (-20 C) = 9.4 ± 2-30 C : EtCNfree : 13.4 ± 0.3 eq EtCN c : 0.65 ± 0.02 ECN nc : 0.09 ± 0.01 K /c (-30 C) = 19 ± 3 K nc/c (-30 C) =7.2 ± 2-40 C : EtCNfree : 12.9 ± 0.3 eq EtCN c : 0.82 ± 0.02 ECN nc : 0.09 ± 0.01 K /c (-40 C) = 71± 10 K nc/c (-40 C) = 9.1 ± 1-50 C : EtCNfree : 12.8 ± 0.3 eq EtCN c : 0.90 ± 0.03 ECN nc : 0.06 ± 0.01 K /c (-50 C) = 180 ± 40 K nc/c (-50 C) = 15.0 ± 3-60 C : EtCNfree : 12.8 ± 0.3 eq EtCN c : 0.94 ± 0.03 ECN nc : 0.04 ± 0.01 K nc/c (-60 C)= 23.5 ± 3 The Van`t Hoff plots (Figure 5) gave the thermodynamic parameters associated to equilibria K /c and K nc/c. S8