ELECTRONIC SUPPORTING INFORMATION

Electronic Supplementary Material (ESI) for New Journal of Chemistry 1 ELECTRONIC SUPPORTING INFORMATION Spin Crossover Polysaccharide Nanocomposites Alexey Tokarev, a Jérôme Long, a Yannick Guari,* a Joulia Larionova, a Françoise Quignard, b Pierre Agulhon, b Mike Robitzer, b Gábor Molnár, c Lionel Salmon, c Azzedine Bousseksou* c. a Institut Charles Gerhardt, UMR 5253, Chimie Moléculaire et Organisation du Solide, Université Montpellier II, Place E. Bataillon, 34095 Montpellier cedex 5, France b Institut Charles Gerhardt, UMR 5253 CNRS-UM2-ENSCM-UM1, Matériaux Avancés pour la Catalyse et la Santé, ENSCM, 8 rue de l Ecole Normale, 34296 Montpellier cedex 5, France c Laboratoire de Chimie de Coordination, CNRS & Université de Toulouse (UPS, INP), 31077 Toulouse, France * Corresponding authors. E-mail: Azzedine.bousseksou@lcc-toulouse.fr, yannick.guari@univ-montp2.fr

Transmittance Electronic Supplementary Material (ESI) for New Journal of Chemistry 2 4000 3500 3000 2500 2000 1500 1000 500 Wavenumber / cm -1 Figure S1. IR spectra of the [Fe(pz)] 2+ /[M(CN) 4 ] 2- /chitosan nanocomposite beads 1 (M = Ni), 2 (M = Pd), 3 (M = Pt) and empty pristine chitosan beads from top to down.

Electronic Supplementary Material (ESI) for New Journal of Chemistry 3 340 K 645 cm -1 190 K 675 cm -1 500 1000 1500 2000 Raman shift (cm -1 ) 645 cm -1 310 K 675 cm -1 190 K 1000 1500 2000 Raman shift (cm -1 ) 310 K 645 cm -1 1000 1500 2000 Raman shift (cm -1 ) Figure S2. Raman spectra of the nanocomposite beads 1 (up), 2 (middle) and 3 (down). Variable-temperature Raman spectra were collected using a LabRAM-HR (Jobin Yvon) Raman spectrometer. The 632.8 nm line of a 17 mw He Ne laser was used as the excitation source, and the exciting radiation was directed through a neutral density filter (OD=2) to avoid sample heating. Samples were enclosed in nitrogen atmosphere on the cold finger of a THMS600 (Linkam) liquid-nitrogen cryostage.

Intensity / a.u. Electronic Supplementary Material (ESI) for New Journal of Chemistry 4 a) Pristine chitosan b) Nanocomposite beads c) Microcrystalline powder 5 10 15 20 25 30 35 40 45 50 2 / deg Figure S3. Powder X-ray diffraction patterns obtained for a) empty pristine chitosan beads; b) [Fe(pz)Ni(CN) 4 ] nanocomposite beads 1; c) [Fe(pz)Ni(CN) 4 ] microcrystalline powder.

Atomic % Atomic % Atomic % Electronic Supplementary Material (ESI) for New Journal of Chemistry 5 57 56 55 54 53 52 51 50 49 Fe Ni 48 47 46 45 44 43 0 200 400 600 800 Distance / m 1000 1200 63 62 61 60 59 58 57 41 40 39 38 Fe Pd 37 0 200 400 600 800 1000 1200 Distance / m 56 55 54 53 52 51 50 49 Fe Pt 48 47 46 45 44 0 200 400 600 800 1000 1200 Distance / m Figure S4. Internal view of the cleaved [Fe(pz)] 2+ /[M(CN) 4 ] 2- /chitosan nanocomposite beads (left) and EDX profile curves (right) showing the Fe/M atomic ratio (%) versus distance ( m) for M= Ni 2+ (top), Pd 2+ (middle), and Pt 2+ (bottom). The analysis includes 20 points of a record through the internal surface of the beads.

O c c u rre n c e Electronic Supplementary Material (ESI) for New Journal of Chemistry 6 140 120 100 80 60 40 20 0 0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0 D ia m e te r / n m 5 0 n m 50 nm Figure S5. TEM images and size distribution of [Fe(pz)] 2+ /[Ni(CN) 4 ] 2- nanoparticles 1 obtained by ultramicrotomy from the surface (upper panel) and in the middle (lower pannel) of a chitosan bead.

Transmittance Electronic Supplementary Material (ESI) for New Journal of Chemistry 7 4000 3500 3000 2500 2000 1500 1000 500 Wavenumber / cm -1 Figure S6. Comparison of the IR spectra of the nanocomposite [Fe(pz)] 2+ /[Ni(CN) 4 ] 2- /chitosan beads (1) (top) and [Fe(pz)] 2+ /[Ni(CN) 4 ] 2- /chitosan film (4) obtained after solubilisation and gelation of 1 (down). 340 K 645 cm -1 170 K 675 cm -1 500 1000 1500 2000 Raman shift (cm -1 ) Figure S7. Raman spectra of the nanocomposite film 4 at 340 and 170 K. Variabletemperature Raman spectra were collected using a LabRAM-HR (Jobin Yvon) Raman spectrometer. The 632.8 nm line of a 17 mw He Ne laser was used as the excitation source, and the exciting radiation was directed through a neutral density filter (OD=2) to avoid sample heating. Samples were enclosed in nitrogen atmosphere on the cold finger of a THMS600 (Linkam) liquid-nitrogen cryostage.

Electronic Supplementary Material (ESI) for New Journal of Chemistry 8 Processing option: All elements analysed (Normalised) Spectrum In stats. Fe Ni Total S(1) Yes 45.04 54.96 100.00 S(2) Yes 44.01 55.99 100.00 S(3) Yes 46.45 53.55 100.00 S(4) Yes 43.01 56.99 100.00 S(5) Yes 43.37 56.63 100.00 S(6) Yes 40.50 59.50 100.00 S(7) Yes 43.68 56.32 100.00 S(8) Yes 44.18 55.82 100.00 S(9) Yes 42.15 57.85 100.00 S(10) Yes 42.14 57.86 100.00 Mean 43.45 56.55 100.00 Std. deviation 1.66 1.66 Max. 46.45 59.50 Min. 40.50 53.55 Processing option: All elements analysed (Normalised) Spectrum In stats. Fe Ni S(1) Yes 46.28 53.72 S(2) Yes 45.24 54.76 S(3) Yes 47.69 52.31 S(4) Yes 44.24 55.76 S(5) Yes 44.61 55.39 S(6) Yes 41.71 58.29 S(7) Yes 44.91 55.09 S(8) Yes 45.42 54.58 S(9) Yes 43.38 56.62 S(10) Yes 43.37 56.63 Mean 44.68 55.32 Std. deviation 1.67 1.67 Max. 47.69 58.29 Min. 41.71 52.31 All results in weight% All results in atomic% Figure S8. (Up left) Surface and (Up right) edge views of the [[Fe(pyrazine){Ni(CN) 4 }]/chitosan nanocomposite film 4 and EDX profile curves showing the Fe and Ni weight (%) (Down left) and atomic ratio (%) (Down right) versus distance (μm) for the edge view.

Electronic Supplementary Material (ESI) for New Journal of Chemistry 9 1,35 1,30 T / cm 3 K mol -1 1,25 1,20 1,15 250 260 270 280 290 300 310 320 T / K Figure S9. Temperature dependence of χt for [Fe(pz)] 2+ /[Pd(CN) 4 ] 2- /chitosan nanocomposite beads recorded between 120 and 320 K at the rate of 1 K min -1. The sample was isothermally held at 383 K (1 h) after 1 st ( -x-, blue) and 2 nd (- -, red) cycles before the 3 rd cycle (- -, green).

Electronic Supplementary Material (ESI) for New Journal of Chemistry 10 1 2 Figure S10. Thermal variation of the reflectivity for nanocomposite beads 1 (2 consecutive cycles following dehydration at 80 C in N 2 flow) and 2 (two consecutive cycles for three different sample positionsfollowing dehydration. Optical microscopy images in the inserts show the color change and the bistability centred at about 12 C.

T / cm 3 K mol -1 Electronic Supplementary Material (ESI) for New Journal of Chemistry 11 1,05 1,00 0,95 0,90 0,85 0,80 0,75 0,70 200 220 240 260 280 300 320 T / K Figure S11. χt dependence vs. temperature for [Fe(pz){Ni(CN) 4 }]/chitosan nanocomposite in the form of aerogel at heating and cooling rates of 1 K min -1. The samples were isothermally held at 393 K during 1 h between the 1 st (-X-) and 2 nd (- -) cycle. Figure S12. Thermal variation of the magnetic susceptibility for sample [Fe(pz){Ni(CN) 4 }]/Alginate nanocomposite beads 5 (aerogel form) at heating (blue curve) and cooling (red curve) rates of 2 Kmin -1

Electronic Supplementary Material (ESI) for New Journal of Chemistry 12 Site Parameters (mm/s) (mm/s) /2 (mm/s) Doublet 1 HS 1 0.855(83) 2.21(14) 0.31(14) Doublet 2 LS 1.564(44) 2.325(66) 0.299(74) Doublet 3 HS 2 0.515(18) 0.722(34) 0.214(28) Compiled Site Properties Site Populations (%) Doublet 1 HS 1 20(10) Doublet 2 LS 36.1(92) Doublet 3 HS 2 44.4(45) Figure S13. Mössbauer measurements for [Fe(pz){Pt(CN) 4 }]/chitosan nanocomposite beads 3 at 80 K. The presence of at least two HS species can be inferred.

Electronic Supplementary Material (ESI) for New Journal of Chemistry 13 80 K 310 K 80 K (mm/s) (mm/s) /2 (mm/s) Doublet 1 1.289(15) 1.992(38) 0.238(29) Doublet 2 0.436(12) 0.664(24) 0.369(17) Doublet 3 1.2238(59) 2.984(17) 0.224(22) Site Populations (%) Doublet 1 HS1 14.2(27) Doublet 2 LS 43.7(11) Doublet 3 HS2 28.1(37) Doublet 4 HS3 14.0(18) 310 K (mm/s) (mm/s) /2 (mm/s) Doublet 1 0.253(38) 0.766(67) 0.25* Doublet 2 0.970(30) 1.411(73) 0.3* Doublet 3 0.776(40) 3.070(78) 0.290(76) Doublet 4 1.226(39) 3.356(68) 0.23* Site Populations (%) Doublet 1 HS1 23.5(24) Doublet 2 LS 30.4(37) Doublet 3 HS2 26.3(77) Doublet 4 HS3 19.8(35) Figure S14. Mössbauer measurements for [Fe(pz){Ni(CN) 4 }]/Alginate nanocomposite beads 5 (aerogel form). The presence of at least three HS iron(ii) species can be inferred.

14 Figure S15. Thermogravimetric analyses of the [Fe(pz)] 2+ /[Ni(CN) 4 ] 2- /chitosan Weight loss / % Weight loss / % 10 % 12 % Electronic Supplementary Material (ESI) for New Journal of Chemistry 100 100 90 90 80 70 60 50 40 80 70 60 50 40 30 0 100 200 300 400 500 600 700 Temperature / o C 30 0 50 100 150 200 250 300 350 400 450 500 Temperature / o C nanocomposite beads 1 (left) and [Fe(pz)] 2+ /[Ni(CN) 4 ] 2- /alginate nanocomposite beads 5 (right) obtained in nitrogen atmosphere with a rate of 2 o C/min. Heat flow / mw mg -1 0,3 0,2 0,1 0,0-0,1-0,2-0,3-0,4-0,5-0,6-0,7 exo -0,8 220 240 260 280 300 320 340 360 380 400 T / K 0,4 0,2 Heat flow / mw mg -1 0,2 0,1 0,0-0,1-0,2-0,3-0,4-0,5-0,6 220 240 260 280 300 320 340 360 380 400 T / K 0,0 Heat flow / mw mg -1-0,2-0,4-0,6-0,8-1,0 220 240 260 280 300 320 340 360 380 400 T / K Figure S16. DSC thermograms recorded for nanocomposite 2 (left, upper panel), 3 (right, upper panel) and 5 (lower panel) in heating and cooling modes with a rate of 10 K min -1 : two cycles between 333 203 K (blue), heating to 403 K with isothermal holding during 1h, and last cycle between 403 203 K (red).