Thiol - Ene click reaction as a general route to functional trialkoxysilanes for surface coating applications

Article abstract of DOI:10.1021/ja202292q

Functionalized trialkoxysilanes are widely used to modify the surface properties of materials and devices. It will be shown that the photoinitiated radical-based thiol - ene "click" reaction provides a simple and efficient route to diverse trialkoxysilanes. A total of 15 trialkoxysilanes were synthesized by reacting either alkenes with 3-mercaptopropyltrialkoxysilane or thiols with allyltrialkoxysilanes in the presence of a photoinitiator. The functionalized trialkoxysilanes were obtained in quantitative to near-quantitative yields with high purity. The photochemical reactions can be run neat in standard borosilicate glassware using a low power 15-W blacklight. A wide range of functional groups is tolerated in this approach, and even complex alkenes click with the silane precursors. To demonstrate that these silanes can be used as surface coating agents, several were reacted with iron oxide superparamagnetic nanoparticles and the loadings quantified. The photoinitiated thiol - ene reaction thus offers a facile and efficient method for preparing surface-active functional trialkoxysilanes.

Full text of DOI:10.1021/ja202292q

Thiol-ene Click Reaction as a General Route to Functional
Trialkoxysilanes for Surface Coating Applications
Alexander K. Tucker-Schwartz, Richard A. Farrell, and Robin L.Garrell*
Department of Chemistry and Biochemistry and California NanoSystems Institute
University of California, Los Angeles
Box 951569
Los Angeles, CA 90095-1569
Tel.(+001) 310-825-2496
Fax: (+001) 310-206-2061
E-mail: garrell@chem.ucla.edu
S1

Table of Contents
Pages
S3
1. General information
2. Alkene precursor synthesis
S4-8
3. Triethoxysilane synthesis from MPTES/alkenes
4. Silane synthesis using MPTMS/alkene or thiol/ATES
5. Large-scale synthesis of diethylacetal trimethoxysilane 3
6. Cost analysis for synthesizing triethoxysilanes 3 and 7
7. UV-Visible spectra of silane 9 and photoiniator
8. Magnetite SPN synthesis and silane surface coating procedures
9. Nanoparticle spectroscopic data
S9-13
S14-16
S17
S18-19
S20
S21
S22-28
S29-77
10. 1H and 13CNMR spectra of synthesized compounds
S2

1. General information
Ferric chloride hexahydrate (FeCl3·6H2O), ferrous chloride tetrahydrate (FeCl2·4H2O), ammonium hydroxide (NH4OH), oleic acid,
sodium sulfate (Na2SO4), magnesium sulfate (MgSO4), hydrochloric acid (HCl), and sodium hydroxide (NaOH) were purchased from
Fisher Scientific(Pittsburgh, PA). 3-mercaptopropyltriethoxysilane (MPTES), 3-mercaptopropyltrimethoxysilane (MPTMS),
allyltriethoxysilane (ATES) were purchased at >95% purity from Gelest Inc.(Morrisville, PA). Diisopropylethylamine, potassium tert-
butoxide (t-BuOK), and tetraethyleneglycol monomethyl ether were purchased from Acros Organics. Allyl bromide, 5-(2-
hydroxyethyl)-4-methylthiazole, 10-undecenoic acid, di-tert-butyl dicarbonate, N,N-dimethylaminepyridine, N-Boc-trans-4-hydroxy-
L-proline methyl ester, 4-penteneoic anhydride, 3-aminoquinuclidine dihydrochloride, dicyclohexylcarbodiimide (DCC), L-serine-tert-
butyl ester, tert-butyl bromoacetate, benzyl hydrosulfide, 2,2-dimethoxy-1,2-diphenylethanone, Celite® 500 fine, and all other alkene
substrates were purchased from Sigma Aldrich (St. Louis, MO). All solvents were HPLC grade and purchased from either EMD
Biosciences, Inc. (Gibbstown, NJ) or Fisher. Dry THF, dioxane, and toluene were prepared by mixing the solvent with MgSO4 and
filtering into hot dry glassware just prior to use. All other solvents and chemicals were used as received.
Hand-held rare-earth magnets, recycled from computer hard drives, were used to separate magnetic nanoparticles from
solution. Sonication was performed using a Branson 2510 ultrasonicator. Fourier transform infrared spectroscopy (FT-IR) was
performed using pressed KBr pellets, or thin liquid films between AgCl plates on a Jasco FT/IR-420. Elemental analysis was
performed on a Flash 1112 series elemental analyzer (Thermo Scientific). Magnetic measurements of particles were made using a
Quantum Design MPMS 5XL Super Quantum Interference Device (SQUID) magnetometer. Transmission electron microscopy (TEM)
images were obtained with an 80-300 kV tunable Titan TEM/STEM. 1H, 13CNMR spectra were obtained using either a Bruker AV300
spectrometer, or Bruker ARX400 spectrometer with a sample changer and CDCl3 or CD3CN as solvents. High resolution mass spectra
were acquired on a Waters LCT Premier XE time-of-flight mass spectrometer; gas chromatography/mass spectrometry (GC/MS) was
performed on a Agilent 6890-5975 GC-MS with autosampler, equipped with an HP-5 column.
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2. Alkene precursor synthesis
2,5,8,11,14-Pentaoxaheptadec-16-ene. An oven-dried 100 mL round bottom flask was charged with t-BuOK (13 mmol), dry THF
(30 mL), purged with argon and cooled to 0°C in an ice bath. Tetraethyleneglycol monomethyl ether (10 mmol) was then added
dropwise to the solution and the reaction stirred at 0°C for 1 h under argon. Allyl bromide (13 mmol) was added dropwise, and the
solution was warmed to R.T. and allowed to stir for 24 h under argon. Deionized water (2 mL) was then added and the reaction stirred
for 10 min. All liquid were then removed in vacuo and the residue redissolved in ethyl acetate (50 mL). The organic was washed three
times with water (20 mL), dried over Na2SO4, filtered over Celite and then concentrated in vacuo to yield clear/light yellow oil (47%).
1HNMR (400 MHz, CDCl3): δ = 5.90 (m, 1H), 5.23 (dd, 1H, 3JHHtrans = 17.3 Hz, , 2JHHgem = 1.7 Hz), 5.15 (dd, 1H, 3JHH = 10.4 Hz, ,
2JHHgem = 1.5 Hz), 4.00 (dd, 2H, 3JHH = 5.89 Hz, , 4JHH = 1.5 Hz), 3.65 (m, 12H), 3.59 (m, 2H), 3.53 (m, 2H), 3.36 (s 3H) ppm.
13CNMR (400 MHz, CDCl3): δ =134.8, 117.0, 72.2, 71.9, 70.6, 70.6, 70.6, 70.5, 69.4, 59.0 ppm. HRMS-ESI: Calculated [M+Na]+:
271.1516; found: 271.1516.
5-(2-(Allyloxy)ethyl)-4-methylthiazole. An oven-dried 100 mL round bottom flask was charged with t-BuOK (20.8 mmol), dry THF
(25 mL), purged with argon and cooled to 0°C in an ice bath. 5-(2-Hydroxyethyl)-4-methylthiazole (16 mmol) was then added
dropwise to the solution and the reaction stirred at 0 °C for 1 h under argon. Allyl bromide (20.8 mmol) was added dropwise, and the
solution was warmed to R.T. and allowed to stir for 20 h under argon. Deionized water (4 mL) was then added and the reaction stirred
for 10 min. All liquid were then removed in vacuo and the residue redissolved in ethyl acetate (50 mL). The organic phase was
washed three times with water (20 mL), dried over Na2SO4, filtered over Celite, and then concentrated in vacuo to yield a yellow oil
(96%).1HNMR (400 MHz, CDCl3): δ = 8.52 (s, 1H), 5.89 (m, 1H), 5.23 (dd, 1H, 3JHHtrans = 17.4 Hz, 2JHHgems = 1.8 Hz), 5.13 (dd, 1H,
3JHHcis = 10.3 Hz, 2JHHgems = 1.6 Hz), 3.96 (dt, 2H, 3JHH = 5.7 Hz, 4JHH = 1.4 Hz), 3.57 (t, 2H, 3JHH = 6.9 Hz), 2.99 (t, 2H, 3JHH = 6.9
Hz), 2.37 (s, 3H) ppm. 13CNMR (400 MHz, CDCl3): δ = 149.6, 149.2, 134.5, 127.9, 17.0, 71.9, 70.0, 27.0, 14.9 ppm. HRMS-ESI:
Calculated [M+H]+: 184.0791; found: 184.0787.
S4

tert-Butyl undec-10-enoate. An oven-dried 50 mL round bottom flask was charged with 10-undeceneoic acid (5 mmol), di-tert-butyl
dicarbonate (10 mmol) and tert-butanol (10 mL). N,N-dimethylaminopyridine (1.5 mmol) was added to the stirred mixture and the
reaction was allowed to stir for 20 h at R.T.. The reaction mixture was concentrated in vacuo and the residue purified by silica gel
chromatography using ethyl acetate/hexanes (2:8) to afford the product as a light yellow oil (58%). Rf=0.98. 1HNMR (400 MHz,
CDCl3): δ = 5.81 (m, 1H), 4.96 (dq, 1H, 3JHH = 17.1 Hz, 4JHH = 1.6 Hz), 4.91 (dq, 1H, 3JHH = 10.2 Hz, 4JHH = 1.2 Hz), 2.19 (t, 2H, 3JHH
= 7.7 Hz), 2.02 (q, 2H, 3JHH = 7.0 Hz), 1.28-1.56 (m, 21H) ppm. 13CNMR (400 MHz, CDCl3): δ = 173.3, 139.2, 114.1, 79.9, 35.6,
33.8, 29.3, 29.2, 29.0, 28.9, 28.1, 25.1 ppm. GC/MS (EI): Calculated [M-C4H9]+: 184.1; found: 184.1.
N-Boc 2-methyl (4R)-4-(pent-4-enoyloxy)pyrrolidine-1,2-dicarboxylate. An oven-dried 50 mL round bottom flask was charged
with N-Boc-trans-4-hydroxy-L-proline methyl ester (1 mmol), N,N-dimethylaminopyridine (0.15 mmol), pyridine (3 mmol), dry
acetonitrile (5 mL), and placed under an argon atmosphere. 4-Pentenoic anhydride (3 mmol) was then added dropwise and the reaction
was warmed to 50 °C and stirred under argon for 44 h. The reaction mixture was then concentrated in vacuo, and the residue dissolved
in THF (5 mL), deionized water (3 mL), pyridine (0.5 mL) and allowed to stir an additional 24 h at 50 °C. The reaction mixture was
then concentrated in vacuo, the residue dissolved in DCM (20 mL), and the DCM washed 1 M HCl (15 mL), water (15 mL), 1 M
NaOH (15 mL), and finally with water (15 mL). The organic was dried over Na2SO4, filtered over Celite, and then concentrated in
vacuo to yield a yellow oil (71%). Diastereomeric mixture (59:41). 1HNMR (400 MHz, CDCl3): δ = 5.80 (m, 1H), 5.29 (m, 1H), 5.03
(m, 2H), 4.39 (dt, 1H, 3JHH = 8.7 Hz), 3.71 (s, 3H), 3.70-3.05 (m, 2H), 2.37 (m, 5H), 2.17 (m, 1H), 1.46 (s, 3H), 1.41 (s, 6H) ppm.
13CNMR (400 MHz, CDCl3): δ = 172.9, 172.7, 172.3, 172.1, 154.0, 153.3, 136.2, 115.6, 80.3, 72.6, 71.8, 57.8, 57.4, 52.2, 52.0, 51.9,
36.5, 35.5, 33.2, 30.2, 29.6, 28.7, 28.2, 28.1 ppm. HRMS-ESI: Calculated [M+Na]+: 350.1574; found: 350.1568.
S5

N-(quinuclidin-3-yl)undec-10-enamide. An oven-dried 50 mL round bottom flask was charged with 3-aminoquinuclidine
dihydrochloride (2 mmol), 10-undecenoic acid (2 mmol), N,N-dimethylaminopyridine (0.3 mmol), diisopropylethylamine (4 mmol),
and dry DMF (15 mL). The flask was purged with argon and cooled to 0°C in an ice bath. Dicyclohexycarbodiimide (2.2 mmol) was
than add to the solution, the flask repurged with argon, and the mixture warmed to R.T. and stirred for 46 h. The reaction mixture was
concentrated in vacuo and 30 ml diethyl ether added to the residue. The solid was filtered off over Celite and the organic phase
concentrated in vacuo. The residue was purified by silica gel chromatography using ethyl acetate/hexanes (3:7) to afford the product
as a white solid (23%). Rf=0.44. 1HNMR (400 MHz, CDCl3): δ = 5.73 (m, 1H), 4.93 (dd, 1H, 3JHH = 17.0 Hz, 4JHH = 1.5 Hz), 4.87 (d,
1H, 3JHH = 10.3 Hz), 3.71(m, 1H), 2.10 (t, 2H, 3JHH = 7.8 Hz), 1.97 (q, 2H, 3JHH = 7.3 Hz), 1.85 (m, 2H), 1.54-1.68 (m, 5H), 1.02-1.34
(m, 15H) ppm. 13CNMR (400 MHz, CDCl3): δ = 172.2, 139.1, 114.1, 48.6, 48.0, 37.0, 34.0, 33.7, 33.2, 29.3, 29.2, 29.0, 28.8, 25.9,
25.7, 25.5, 25.0, 24.9 ppm. HRMS-ESI: Calculated [M-C2H2]+: 266.2358; found: 266.2474.
OH O
O
O
O
N
O
O
(S)-tert-Butyl-2-di(tert-butyloxycarbonylmethyl)amino-3-hydroxypropanoate. This material was prepared following a previously
reported protocol (Meunier, S.; Cristau, P.; Taran, F. Synth. Commun. (2005), 35,2415-2425). An oven-dried 100 mL round bottom
flask was charged with L-serine tert-butyl ester hydrochloride (4 mmol), diisopropylethylamine (24 mmol), and acetonitrile (25 mL).
tert-butyl bromoacetate (16 mmol) was then added dropwise and the entire mixture refluxed in air for 24 h. The reaction mixture was
concentrated in vacuo and ethyl acetate (40 mL) added and the resulting precipitate filtered off over Celite. The ethyl acetate was then
concentrated in vacuo and the residue purified by silica gel chromatography using ethyl acetate/hexanes (2:8) to afford the product as
a light yellow solid (68%). Rf=0.56. 1HNMR (400 MHz, CDCl3): δ = 4.21 (d, 1H, 3JHH = 10.9 Hz), 3.69 (td, 1H, 2JHH = 10.8 Hz, 3JHH
S6

= 13.6 Hz), 3.42 (m, 6H), 1.40 (s, 27H) ppm. 13CNMR (400 MHz, CDCl3): δ = 171.3, 107.2, 81.7, 81.3, 68.2, 60.1, 54.9, 28.1, 28.0
ppm. HRMS-ESI: Calculated [M+H]+: 390.2488; found: 390.2470.
O
O
O
O
O
O
N
O
O
(S)-tert-Butyl-2-di(tert-butyloxycarbonylmethyl)amino-3-(pent-4-enoyloxy)-propanoate. An oven-dried 50 mL round bottom
flask was charged with (S)-tert-butyl-2-di(tert-butyloxycarbonylmethyl)amino-3-hydroxypropanoate (1 mmol), N,N-
dimethylaminopyridine (0.3 mmol), diisopropylethylamine (3 mmol), acetonitrile (5 mL), and purged with argon. 4-pentenoic
anhydride (3 mmol) was then slowly added dropwise and the reaction mixture stirred under agron at 55 °C for 42 h. The reaction
mixture was concentrated in vacuo and the residue dissolved in THF (5 mL), deionized water (1 mL), pyridine (0.5 mL), capped, and
stirred at 55 °C for 24 h. Solvents were concentrated in vacuo and the residue purified by silica gel chromatography using ethyl
acetate/hexanes (1:9) to afford the product as a light yellow oil (96%). Rf=0.49. 1HNMR (400 MHz, CDCl3): δ = 5.80 (m, 1H), 5.05
(dq, 1H, 3JHH = 17.2 Hz, 4JHH = 1.6 Hz), 4.97 (dq, 1H, 3JHH = 10.2 Hz, 4JHH = 1.4 Hz), 4.42 (dd, 1H, 2JHH = 10.9 Hz, 3JHH = 5.9
Hz),4.29 (dd, 1H, 2JHH = 11.2 Hz, 3JHH = 6.7 Hz), 3.69 (t, 1H, 3JHH = 5.6 Hz), 3.55 (s, 2H), 3.54 (s, 2H), 2.36 (m, 4H), 1.45 (s, 9H),
1.44 (s, 18H) ppm. 13CNMR (400 MHz, CDCl3): δ = 172.4, 170.6, 169.6, 136.6, 115.5, 81.7, 80.8, 63.8, 63.5, 54.3, 33.4, 28.7, 28.1
ppm. HRMS-ESI: Calculated [M+H]+: 472.2905; found: 472.2924.
S7

((2-(allyloxy)-2-oxoethyl)amino)(amino)methaniminium 2,2,2-trifluoroacetate. An oven-dried 100 mL round bottom flask was
charged with guanidineacetic acid (4.32 mmol), trifluoroacetic acid (20 mL), and allyl alcohol (15 mL) and the reaction mixture
refluxed 48 h. The reaction mixture was concentrated in vacuo and the residue purified by silica gel chromatography
chloroform/methanol (7:3) to afford the product as a viscous yellow oil (52%). Rf=0.82 . 1HNMR (400 MHz, CD3CN): δ = 7.79 (bt,
1H, 3JHH = 5.3 Hz), 7.15 (bs, 1H), 5.90 (m, 1H), 5.33 (dd, 1H, 3JHH = 17.3 Hz, 4JHH = 1.4 Hz), 5.23 (dd, 1H, 3JHH = 10.3 Hz, 4JHH = 1.4
Hz), 4.61 (d, 2H, 3JHH = 5.6 Hz),4.01 (d, 2H, 3JHH = 6.1 Hz) ppm. 13CNMR (400 MHz, CD3CN): δ = 169.6, 159.2, 159.2, 159.1,
132.9, 132.8, 132.8, 119.0, 67.1, 67.0, 66.9, 43.7, 43.6 ppm. 13CNMR (400 MHz, CD3CN): δ = -77.5 ppm. HRMS-ESI: Calculated
[M]+: 158.0930; found: 158.0927.
S8

3. Triethoxysilane synthesis
General procedure. A cooled oven-dried 10-mL round bottom was charged with MPTES (1 equiv.), alkene (1 equiv.) and 2 mol%
2,2-dimethoxy-1,2-diphenylethanone (0.02 equiv.), known commercially as Irgacure®651. The reaction was run neat unless the
alkene did not fully dissolve, in which case a tiny amount of dry chloroform or methanol was added. The reaction mixture was then
capped with a septum and purged briefly with argon or nitrogen. The flask was placed next to an 15 W, 18”-long blacklight having a
total UV output of 2.6 W and λmax = 368 nm. The flask was positioned so that one side rested against the center of the bulb. The UV
flux at λmax = 368 nm was measured to be 30% attenuated after passing through standard thickness Pyrex glass beaker. Both the flask
and blacklight were wrapped in aluminum foil and the reaction mixture irradiated on average for 24 h with gentle stirring to yield
product silanes in high purity. If solvent was added to the reaction, it was removed in vacuo upon completion of the reaction. Product
conversion and purity were determined by 1HNMR or GC/MS.
PEG triethoxysilane (1). Following the general procedure above, MPTES (2 mmol), 2,5,8,11,14-pentaoxaheptadec-16-ene (2 mmol),
and Irgacure®651 (0.04 mmol) were mixed, purged with argon, and irradiated 24 h (>99% conversion, 96% pure). 1HNMR (400
MHz, CDCl3): δ = 3.78 (q, 2H, 3JHH = 6.7 Hz), 3.35-3.65 (m, 18H), 3.37 (s, 3H),2.56 (t, 2H, 3JHH = 7.6 Hz), 2.52 (t, 2H, 3JHH = 7.2
Hz), 1.82 (m, 2H), 1.68 (m, 2H), 0.726 (t, 3JHH = 8.5 Hz) ppm. 13CNMR (400 MHz, CDCl3): δ = 70.6, 70.6, 70.6, 70.6, 70.5, 70.5,
70.2, 69.8, 59.0, 58.4, 35.2, 29.7, 28.6, 23.2, 18.3, 9.9 ppm. HRMS-ESI: Calculated [M+Na]+: 509.2575; found: 509.2552.
Thiazole triethoxysilane (2). Following the general procedure above, MPTES (5 mmol), 5-(2-(allyloxy)ethyl)-4-methylthiazole (5
mmol), and Irgacure®651 (0.1 mmol) were mixed, purged with argon, and irradiated 24 h (>99% conversion, 95% pure). 1HNMR
(400 MHz, CDCl3): δ = 8.54 (s, 1H), 3.78 (q, 6H, 3JHH = 7.2 Hz), 3.56 (t, 2H, 3JHH = 6.6 Hz), 3.50 (t, 2H, 3JHH = 6.1 Hz), 2.98 (t, 2H,
3JHH = 6.4 Hz), 2.56 (t, 2H, 3JHH = 7.2 Hz), 2.50 (t, 2H, 3JHH = 7.2 Hz), 2.37 (s, 3H), 1.14 (t, 9H, 3JHH = 6.7 Hz), 0.71 (t, 2H, 3JHH=7.7
S9

Hz) ppm. 13CNMR (400 MHz, CDCl3): δ = 149.6, 149.1, 128.0, 70.6, 69.5, 58.4, 35.1, 29.8, 28.6, 27.0, 23.0, 18.3, 14.9, 9.9 ppm.
HRMS-ESI: Calculated [M+H]+: 422.1850; found: 422.1850.
OEt
S
3
OEt
(EtO)3Si
Diethyl acetal triethoxysilane (3). Following the general procedure above, MPTES (2 mmol), acrolein diethyl acetal (2 mmol), and
Irgacure®651 (0.04 mmol) were mixed, purged with argon, and irradiated 24 h (>99% conversion, 96% pure). 1HNMR (400 MHz,
CDCl3): δ = 4.95 (t, 1H, 3JHH = 5.6 Hz), 3.80 (q, 6H, 3JHH = 7.1 Hz), 3.64 (m, 2H), 3.49 (m, 2H), 2.53 (q, 4H, 3JHH = 6.6 Hz), 1.88 (m,
2H), 1.70 (m, 2H), 1.20 (m, 15H), 0.72 (t, 2H, 3JHH = 8.1 Hz) ppm. 13CNMR (400 MHz, CDCl3): δ = 101.17, 61.5, 58.4, 35.2, 33.9,
27.1, 23.2, 18.3, 15.3, 9.9 ppm. HRMS-ESI: Calculated [M+Na]+: 391.1945; found: 391.1932.
tert-Butyl undecanoate triethoxysilane (4). Following the general procedure above, MPTES (2 mmol), tert-butyl undec-10-enoate (2
mmol), and Irgacure®651 (0.04 mmol) were mixed, purged with argon, and irradiated 24 h (>98% conversion, 96% pure). 1H NMR
(400 MHz, CDCl3): δ = 3.81 (q, 6H, 3JHH = 6.9 Hz), 2.52 (t, 2H, 3JHH = 7.2 Hz), 2.48 (t, 2H, 3JHH = 7.2 Hz), 2.19 (t, 2H, 3JHH = 7.6
Hz), 1.68 (m, 2H), 1.56 (m, 4H), 1.43 (s, 9H), 1.36 (m, 12H), 1.22 (t, 9H, 3JHH = 7.2 Hz), 0.73 (t, 2H, 3JHH = 8.4 Hz) ppm. 13CNMR
(400 MHz, CDCl3): δ = 173.3, 79.9, 58.4, 35.6, 35.2, 32.0, 29.8, 29.5, 29.4, 29.3, 29.2, 29.1, 29.0, 28.1, 25.1, 23.3, 18.3, 9.9 ppm.
HRMS-ESI: Calculated [M+Na]+: 501.3046; found: 501.3050.
S10

Thiourea triethoxysilane (5). Following the general procedure above, MPTES (2 mmol), N-allylthiourea (2 mmol), Irgacure®651
1
(0.04 mmol), and dry MeOH (0.6 mL) were mixed, purged with argon, and irradiated 24 h (>99% conversion, 95% pure). HNMR
(400 MHz, CDCl3): δ = 6.61 (bs, 1H), 5.94 (bs, 1H), 3.77 (q, 6H, 3JHH =6.6 Hz), 3.51 (bs, 1H), 2.51 (q, 4H, 3JHH = 7.3 Hz), 2.16 (s,
2H), 1.77 (m, 2H), 1.62 (m, 2H), 1.59 (t, 9H, 3JHH =7.4 Hz), 0.68 (t, 2H, 3JHH = 8.2 Hz) ppm. 13CNMR (400 MHz, CDCl3): δ = 182.9,
58.2, 34.7, 28.9, 22.9 ppm. HRMS-ESI: Calculated [M+Na]+: 377.1365; found: 377.1368.
Mix of diestereomers (59:41)
N-Boc-(4R)-4-hydroxy-L-proline methyl ester triethoxysilane (6). Following the general procedure above, MPTES (0.66 mmol), N-
Boc 2-methyl (4R)-4-(pent-4-enoyloxy)pyrrolidine-1,2-dicarboxylate (0.66 mmol), and Irgacure®651 (0.013 mmol) were mixed,
purged with argon, and irradiated 24 h (96% conversion, 94% pure). 1HNMR (400 MHz, CDCl3): δ = 5.28 (s, 1H), 4.34 (dt, 1H, 3JHH
= 8.3 Hz), 3.82 (q, 6H, 3JHH = 6.9 Hz), 3.49-3.74 (m, 5H), 2.51 (q, 4H, 3JHH = 7.3 Hz), 2.36 (m, 1H 2.32 (t, 2H, 3JHH = 7.7 Hz), 2.19,
(m, 1H), 1.68 (m, 6H), 1.45 (s, 3H), 1.41 (s, 6H), 1.22 (t, 9H, 3JHH = 7.2 Hz), 0.73 (t, 2H, 3JHH = 8.0) ppm. 13CNMR (400 MHz,
CDCl3): δ = 173.1, 172.8, 172.7, 154.2, 153.5, 80.5, 72.5, 71.8, 58.4, 57.9, 57.5, 52.3, 52.2, 52.1, 52.0, 36.6, 35.6, 35.1, 33.8, 31.4,
29.0, 28.3, 28.2, 24.0, 23.2, 18.3, 9.9 ppm. HRMS-ESI: Calculated [M+Na]+: 588.2639; found: 588.2649.
S11

Quinuclidine triethoxysilane (7). Following the general procedure above, MPTES (0.41 mmol), N-(quinuclidin-3-yl)undec-10-
enamide (0.41 mmol), Irgacure®651 (0.008 mmol), and dry CHCl3 (0.5 mL) were mixed, purged with argon, and irradiated 24 h
(>98% conversion, 96% pure). 1HNMR (400 MHz, CDCl3): δ = 5.34 (s, 1H), 3.80 (m, 6H), 2.52 (t, 2H, 3JHH = 7.5 Hz), 2.48 (t, 2H,
3JHH = 7.5 Hz), 2.11 (t, 2H, 3JHH = 7.8 Hz), 1.57-1.89 (m, 12H), 1.23 (m, 26H), 0.73 (t, 2H, 3JHH = 8.2 Hz) ppm. 13CNMR (400 MHz,
CDCl3): δ = 172.1, 129.1, 77.2, 67.1, 58.4, 58.2, 48.0, 37.1, 35.2, 33.3, 32.0, 29.8, 29.5, 29.4, 29.3, 29.2, 29.0, 25.9, 25.6, 24.9, 23.2,
18.3, 9.9 ppm. HRMS-ESI: Calculated [M-C3H6NO]+:458.3124; found: 458.3134.
Quinine triethoxysilane (8). Following the general procedure above, MPTES (1 mmol), quinine (1 mmol), Irgacure®651 (0.02
mmol), and dry CHCl3 (1 mL) were mixed, purged with argon, and irradiated 27 h (>98% conversion, 96% pure). 1HNMR (400 MHz,
CDCl3): δ = 8.63 (d, 1H, 3JHH = 4.6 Hz), 7.95 (d, 1H, 3JHH = 9.2 Hz), 7.47 (d, 1H, 3JHH = 5.1 Hz), 7.31 (dd, 1H, 3JHH = 9.2 Hz, 4JHH
=
2.6 Hz), 7.22 (d, 1H, 4JHH = 2.0 Hz), 5.51 (s, 1H), 3.98 (s, 3H), 3.78 (q, 6H, 3JHH = 7.1 Hz),3.58 (bs, 1H), 3.42 (bs, 1H), 3.06 (m, 2H),
2.65 (m, 1H), 2.45 (t, 2H, 3JHH = 7.1 Hz), 2.39 (t, 2H, 3JHH = 7.1 Hz), 1.42-1.75 (m, 10H), 1.19 (t, 9H, 3JHH = 6.6 Hz), 0.67 (t, 2H, 3JHH
= 8.2 Hz) ppm. 13CNMR (400 MHz, CDCl3): δ = 157.8, 147.6, 144.3, 131.6, 126.6, 121.5, 118.4, 117.5, 101.3, 77.2, 72.0, 59.8, 58.4,
43.2, 35.2, 34.7, 34.7, 30.0, 28.2, 25.7, 23.2, 21.7, 18.3, 9.9 ppm. HRMS-ESI: Calculated [M+H]+: 563.2969; found: 563.2977.
S12

O
S
(EtO)3Si
O
O
3
4
O
O
O
N
O
O
Nitrilotriacetate (NTA) triethoxysilanesilane (9). Following a similar procedure to the one described above, MPTES (0.5 mmol),
(S)-tert-butyl-2-di(tert-butyloxycarbonylmethyl)amino-3-(pent-4-enoyloxy )propanoate (0.5 mmol), and Irgacure®651 (0.015 mmol,
3 mol %) were mixed, purged with argon, and then gently warmed in an oil bath until the Irgacure®651 dissolved. The mixture was
then irradiated 45 h. Following, an additional amount of Irgacure®651 (0.01 mmol, 2 mol%) was added to the reaction, the flask
purged, and the mixture irradiated an additional 22 h (94% conversion, 90% pure). 1HNMR (400 MHz, CDCl3): δ = 4.41 (dd, 1H, 2JHH
= 10.9 Hz, 3JHH = 5.8 Hz),4.27 (dd, 1H, 2JHH = 10.9 Hz, 3JHH = 6.9 Hz), 3.81 (q, 6H, 3JHH = 6.9 Hz), 3.68 (t, 1H, 3JHH = 6.6 Hz), 3.54
(d, 3H, 4JHH = 2.8 Hz), 2.50 (m, 4H), 2.30 (t, 2H, 3JHH = 7.5 Hz), 1.57-1.71 (m, 6H), 1.45 (m, 28H), 1.21 (t, 9H, 3JHH = 7.1 Hz), 0.72
(t, 2H, 3JHH = 8.3 Hz) ppm. 13CNMR (400 MHz, CDCl3): δ = 172.7, 170.5, 169.6, 81.8, 80.8, 63.8, 63.4, 58.4, 54.2, 35.1, 33.6, 31.5,
29.1, 28.1, 24.0, 23.2, 18.3, 9.9 ppm. HRMS-ESI: Calculated [M+H]+: 710.3964; found: 710.3981 ppm.
OAc
O
O
S
(EtO)3Si
OAc
OAc
3
OAc
Tetra-O-acetyl-β-D-glucopyranoside triethoxysilane (10). Following the general procedure above, MPTES (1 mmol), allyl-tetra-O-
acetyl-β-D-glucopyranoside (1 mmol), Irgacure®651 (0.02 mmol), and dry CHCl3 (0.6 mL) were mixed, purged, and irradiated 25 h
(>99% conversion, 97% pure). 1HNMR (400 MHz, CDCl3): δ = 5.30 (s, 2H), 5.20 (t, 1H, 3JHH = 8.9 Hz), 5.07 (t, 1H, 3JHH = 9.5 Hz),
4.97 (t, 1H, 3JHH = 8.9 Hz), 4.50 (d, 1H, 3JHH = 8.9 Hz), 4.28 (dd, 1H, 3JHH = 12.5 Hz, 3JHH = 4.8 Hz), 4.14 (dd, 1H, 3JHH = 12.5 Hz,
3JHH = 2.4 Hz), 3.70 (dt, 1H, 3JHH = 10.1 Hz, 3JHH = 5.4 Hz), 3.82 (q, 6H, 3JHH = 7.2 Hz), 3.62 (m, 2H), 2.53 (q, 4H, 3JHH = 7.7 Hz),
2.08 (s, 3H), 2.04 (s, 3H), 2.02 (s, 3H), 2.00 (s, 3H), 1.80 (m, 2H), 1.67 (m, 2H), 1.22 (t, 9H, 3JHH=7.1 Hz) 0.73 (t, 2H, 3JHH=8.3 Hz)
ppm. 13CNMR (400 MHz, CDCl3): δ = 170.7, 170.3, 169.4, 169.3, 101.0, 72.9, 71.8, 71.3, 68.5, 62.0, 58.4, 53.4, 53.1, 29.4, 28.2,
23.2, 20.8, 20.7, 20.6, 20.6, 18.3, 10.0 ppm. HRMS-ESI: Calculated [M+Na]+: 422.1850; found: 422.1850.
S13

4. Silane synthesis using MPTMS or thiol/ATES.
General procedure. A cooled oven-dried 10-mL round bottom was charged with either MPTMS, alkene (1 equiv.) and 2 mol%
Irgacure®651, or ATES (1 equiv.), or thiol (1 equiv.) and 2 mol% Irgacure®651. The reaction was run neat unless one of the reactants
did not fully dissolve; in which case a tiny amount of dry chloroform, or methanol was added. The reaction mixture was then capped
with a septum and purged briefly with argon or nitrogen. The flask was placed next to an 18” 15 W blacklight, with total UV output of
2.6 W and λmax = 368 nm, so that the flask’s side rested against the center of the bulb. The UV flux at λmax = 368 nm was measured to
be attenuated ~30% after passing through standard thickness Pyrex glass. Both the flask and UV blacklight were wrapped in
aluminum foil and the reaction mixture irradiated for 24 hours with gentle stirring to yield products in high purity. If solvent was
added to the reaction, it was removed upon reaction completion in vacuo.
Acetal trimethoxysilane (11). Following the general procedure above, MPTMS (2 mmol), acrolein diethyl acetal (2 mmol),
Irgacure®651 (0.04 mmol), were mixed, purged, and irradiated 24 h (>99% conversion, 96% pure). 1HNMR (400 MHz, CDCl3): δ =
4.59 (t, 1H, 3JHH = 5.5 Hz), 3.64 (m, 2H), 3.54 (s, 9H), 3.49 (m, 2H), 2.52 (q, 4H, 3JHH = 7.5 Hz), 1.86 (m, 2H), 1.69 (m, 2H), 1.19 (t,
6H, 3JHH = 7.0 Hz), 0.74 (t, 2H, 3JHH = 8.1 Hz) ppm. 13CNMR (400 MHz, CDCl3): δ = 101.7, 61.5, 50.5, 35.1, 33.8, 27.1, 22.9, 15.3,
8.6 ppm. HRMS-ESI: Calculated [M+Na]+: 349.1475; found: 349.1478.
Undecanoic acid trimethoxysilane (12). Following the general procedure above, MPTMS (2.5 mmol), 10-undecenoic acid (2.5
mmol), Irgacure®651 (0.05 mmol), and dry CHCl3 (0.5 mL) were mixed, purged, and irradiated 24 h (>99% conversion, 96% pure).
1HNMR (400 MHz, CDCl3): δ = 3.56 (s, 9H), 2.50 (m, 4H), 2.34 (t, 2H, 3JHH = 7.8 Hz), 1.60 (m, 6H), 1.32 (m, 12H), 0.75 (t, 2H, 3JHH
= 8.1 Hz) ppm. 13CNMR (400 MHz, CDCl3): δ = 179.5, 117.7, 50.5, 35.1, 34.0, 32.0, 29.7, 29.4, 29.3, 29.2, 29.0, 28.9, 24.7, 23.0, 8.6
ppm. HRMS-ESI: Calculated [M-H]¯: 379.1980; found: 379.1992.
S14

Guanidinum triethoxysilane (13). Following the general procedure above, MPTMS (1.0 mmol), ((2-(allyloxy)-2-
oxoethyl)amino)(amino)methaniminium 2,2,2-trifluoroacetate (1.0 mmol), Irgacure®651 (0.05 mmol), and dry CH3CN (0.7 mL) were
mixed, purged, and irradiated 24 h (>99% conversion, 95% pure). The final product contained some dimerized silane due to reaction
of 13 with small amounts of water trapped in the guanidinium salt. Formation of the dimer was determined from analysis of the high
resolution mass spectrum, 1HNMR, and 13CNMR spectra. 1HNMR (400 MHz, CD3CN): δ = 7.81 (bs, 1H), 7.16 (bs, 4H), 4.20 (t, 2H,
3JHH = 6.4 Hz), 3.96 (bs, 2H), 3.49 (s, 5H), 2.52 (m, 4H), 1.87 (m, 2H), 1.62 (m, 2H), 0.72 (t, 2H, 3JHH = 7.9 Hz) ppm. 13CNMR (400
MHz, CD3CN): δ = 168.7, 168.6, 168.6, 158.2, 64.2, 7, 42.7, 34.2, 28.4, 27.5, 22.9, 22.8, 9.5, 9.4, 8.0 ppm. 13FNMR (400 MHz,
CD3CN): δ = -76.6 ppm. HRMS-ESI: Calculated [M-C2O2F3]+: 354.1519; found: 354.1518. Calculated for dimer [2M- 2C2O2F3-
2MeO-H]+: 661.2535; found: 661.2549.
Benzyl triethoxysilane (14). Following the general procedure above, ATES (2 mmol), benzyl hydrosulfide (2 mmol), Irgacure®651
(0.04 mmol), were mixed, purged, and irradiated 24 h (>99% conversion, 97% pure). 1HNMR (400 MHz, CDCl3): δ = 7.30 (m, 4H),
7.23 (m, 1H), 3.80 (q, 6H, 3JHH = 7.0 Hz), 3.70 (s, 2H), 2.44 (t, 2H, 3JHH = 7.3 Hz), 1.66 (m, 2H), 1.22 (t, 9H, 3JHH = 7.0 Hz), 0.70 (t,
2H, 3JHH = 8.3 Hz) ppm. 13CNMR (400 MHz, CDCl3): δ = 138.7, 128.8, 128.4, 126.9, 58.4, 36.1, 34.4, 22.8, 18.3, 9.9 ppm. HRMS-
ESI: Calculated [M-C4H9O]+: 255.0870; found: 255.0874.
S15

O
S
O
(EtO)3Si
HN
Boc
Boc-cysteine-OMe triethoxysilane (15). Following the general procedure above, ATES (2 mmol), N-(tert-butoxycarbonyl)-L-
cysteine methyl ester (2 mmol), Irgacure®651 (0.04 mmol), were mixed, purged, and irradiated 24 h (>99% conversion, 97% pure).
1HNMR (400 MHz, CDCl3): δ = 5.43 (d, 1H, 3JHH= 7.7 Hz), 4.51 (q, 1H, 2JHH = 14.5 Hz, 3JHH = 4.9 Hz), 3.80 (q, 6H, 3JHH = 7.0 Hz),
3.74 (s, 3H), 2.93 (d, 2H, 3JHH = 4.6 Hz), 2.52 (t, 2H, 3JHH = 7.3 Hz), 1.65 (m, 2H), 1.43(s, 9H), 1.20 (t, 9H, 3JHH = 6.6 Hz), 0.69 (t,
2H, 3JHH = 8.4 Hz) ppm. 13CNMR (400 MHz, CDCl3): δ = 171.6, 155.1, 80.0, 58.3, 53.2, 52.4, 35.6, 34.3, 28.3, 23.1, 18.3, 9.8 ppm.
HRMS-ESI: Calculated [M+H]+: 440.2138; found: 440.2123.
S16

5. Large-scale synthesis of 3
A cooled oven-dried Pyrex glass tube (7.5” tall, 1” diameter) with a 29/42 joint was charged with MPTES (107 mmol), acrolein
diethyl acetal (107 mmol), Irgacure®651 (2.1 mmol), and then capped with a septum purged briefly with argon. The small tube
diameter made it possible for the maximum amount of light to illuminate the reaction mixture. The tube was placed next to two 15 W,
18” long blacklights, each having a total UV output of 2.6 W (λmax = 368 nm). The tube was positioned so that each blacklight just
rested against each side of the tube, (See Figure S1 below.) The flask and blacklights were wrapped in aluminum foil and the reaction
mixture irradiated for 24 h with gentle stirring to yield product silanes in high purity (>99% conversion, 93% pure). 1HNMR (400
MHz, CDCl3): δ = 4.95 (t, 1H, 3JHH = 5.6 Hz), 3.80 (q, 6H, 3JHH = 7.1 Hz), 3.64 (m, 2H), 3.49 (m, 2H), 2.53 (q, 4H, 3JHH = 6.6 Hz),
1.88 (m, 2H), 1.70 (m, 2H), 1.20 (m, 15H), 0.72 (t, 2H, 3JHH = 8.1 Hz) ppm. 13CNMR (400 MHz, CDCl3): δ = 101.17, 61.5, 58.4, 35.2,
33.9, 27.1, 23.2, 18.3, 15.3, 9.9 ppm.
a
b
c
Figure S1. Images of setup for large-scale synthesis of 3: a) prior to, and b) during reaction. c) Image of reaction tube containing product 3 after the
reaction was complete.
S17

6. Cost analysis for synthesizing triethoxysilanes 3 and 7
The estimates provided here of the material cost to produce triethoxysilanes 3 and 7 via the thiol-ene reaction were simplified by only
considering the cost of the chemicals. [The blacklights, stir plate, glassware, and energy required to power the lamps were not
included because the equipment is reusable and the blacklights we used are very inexpensive.]
The cost estimates for producing 3 and 7 per mmol material are shown below in Schemes S1 and S2, respectively. Starting materials
to prepare 3 and 7 included 25 g acrolein diethyl acetal (≥96%), 5 g quinine (suitable for fluorescence, anhydrous, ≥98.0%), 50 g 2,2-
dimethoxy-1,2-diphenylethanone (>99%) purchased from Sigma Aldrich, and 25g MPTES (≥95%) purchased from Gelest Inc.
The estimated cost to prepare 3 is $0.61/mmol 3. The retail price of the chemically similar, commercially available
triethoxysilylundecanal ethylene glycol acetal (Gelest catalog #: SIT8194.5) is 13 times higher.
$0.33/mmol
$0.28/mmol
$0.20/mmol
$0.20/mmol*(0.02)
+
$0.33/mmol
$0.28/mmol
= $0.61/mmol
Scheme S1. Synthesis of diethyl acetal triethoxysilane 3 and cost of materials.
S18

The estimated cost to prepare 7 is $3.44/mmol. For comparison, the price of (R)-N-triethoxysilylpropyl quinine urethane (Gelest
catalog #: SIT8192.4) is 4 times higher.
$0.33/mmol
$3.11/mmol
$0.20/mmol
$0.20/mmol*(0.02)
+
O
$0.33/mmol
$3.11/mmol
H
= $3.44/mmol
Ph
Ph
S
(EtO)3Si
MeO OMe
2 mol %
3
SH +
MeO
(EtO)3Si
N
H
N
UV Light
OH
OH
MeO
N
N
Scheme S2. Synthesis of quinine triethoxysilane 7 and cost of materials.
S19

7. UV-visible spectra of silane 9 and photoinitiator.
Figure S2 shows an overlay of the UV-visible spectra of silane 9 (0.3 M) and the Irgacure® 651 photoinitiator (0.003 M). At 368 nm,
λmax for the blacklight used to drive the thiol-ene reaction, there is a little overlap of the absorption bands of the photoinitiator and
product. Despite the large difference in molar extinction coefficients at 368 nm, one must remember that the photoinitiator is present
at only at 2 mol% while the silane is extremely concentrated. Consequently, there is significant absorbance overlap at 365 nm. This
absorbance overlap is believed to be a factor that prevents the reaction of MPTES (0.5 mmol) and (S)-tert-butyl-2-di(tert-
butyloxycarbonylmethyl)amino-3-(pent-4-enoyloxy )propanoate from reaching completion. The other contributing factor is thought to
be the increase in the solution viscosity of the reaction as it proceeds, which limits mass transport.
UV-Visible Spectra of 9 and Irgacure® 651
0.3 M NTA silane (9)
0.003 M Irgacure 651
250
200
λ=368 nm
150
100
50
0
350
360
370
380
390
400
Wavelength (nm)
Figure S2. UV-visible spectra of 0.3 M NTA silane 9 in chloroform (black line) and 0.003 M Irgacure® 651 in chloroform
(blue line) with the y-axis normalized to concentration and sample path length..
S20

8. Nanoparticle synthesis and silane surface coating procedure.
8.1-Preparation of oleic acid-coated Fe3O4 superparamagnetic nanoparticles (SPNs). Core magnetite SPNs were synthesized by
the method previously described.1 Briefly, 1 mL of an aqueous 3.0 M FeCl2, 2 M HCl solution was mixed with 4 mL of 1.5 M FeCl3,
2 M HCl on a magnetic stir plate at R.T. The iron chloride solution was then slowly titrated dropwise with 50 mL of 1.05 M NH4OH
over a period of about 30 min, producing a deep black particle suspension. The superparamagnetic magnetite nanoparticles were
separated using a hand-held neodymium rare-earth magnet and washed three times with water, three times with acetone, and then air-
dried for at least 3 h. The collected particles were crushed, weighed and placed in a screw-cap glass vial. An equal weight of oleic acid
was added to the vial along with 1 mL ethyl acetate per 0.1 g SPNs. The vial was capped and sonicated for 2 h at 60 °C. The
suspension was cooled, and the particles were magnetically separated, washed three times with excess ethyl acetate, three times with
methanol, and then dried under vacuum. The final product was crushed to yield a black/dark brown powder.
8.2- General procedure for functionalizing Fe3O4 SPNs with triethoxysilanes 1–10. The goal of these experiments was simply to
determine whether the triethoxysilanes 1–10 could be covalently attached to magnetite SPN surfaces and detected. Because we were
not concerned with the relative surface reactivities of the silanes, the amount of silane used in the reaction was not tightly controlled.
In most cases, the triethoxysilanes were made on ≥1 mmol scale, and 1 mmol was used to coat the SPNs. In a few cases, <1 mmol was
synthesized, and all of the product was used to coat the SPNs.
Oleic acid-coated SPNs (120 mg), and either toluene or dioxane (60 mL), passed over MgSO4 just prior to use, were added to a hot,
oven-dried 100 mL round bottom flask. The flask was immediately capped and purged with argon for 5 min. The flask was then
placed in an ultrasonication bath at R.T. and sonicated for 20 min to redisperse the oleic acid-coated SPNs. Then a stir bar was quickly
added to the flask, which was immediately capped and purged 5 min with argon while vigorously stirring the particle suspension to
prevent the SPNs from sticking to the stir bar. An argon balloon was placed on the flask and a triethoxysilane (0.4 to 1 mmol; see
Table S1 for exact quantity of added silane) was added to the flask dropwise. The flask was placed in a 75 °C oil bath and heated for
24 h with vigorous stirring. The stir bar was removed and the particles were separated using a hand-held rare-earth magnet, washed
three times with either diethyl ether or CHCl3, and then dried under vacuum.
S21

9. Nanoparticle spectroscopic data.
9.1- Elemental analysis of silane loadings on coated SPNs. All triethoxysilanes used to coat the SPNs contained at least one sulfur
atom present in the thioether bridge formed during synthesis of the silane. This allowed quantification of silane loadings on coated
SPNs by sulfur elemental analysis. The experimentally-determined loadings are given in Table S1. Nearly all of the thiol-ene reactions
used to produce these silanes reached ≥98% conversion. The crude products contained virtually no MPTES, which, if present, could
bind to the surface and contribute to the measured sulfur content. Hence, for the reactions with >98% reactant conversions, we have
assumed that the measured SPN sulfur content of the silane-coated particles derived only from the functional triethoxysilane. For the
two cases in which the reactions reached only 94% or 96% conversion (6, 9), we have assumed that the percentage of the measured
sulfur content that is attributable to surface-bound functional triethoxysilane is at best equal to the percent purity of the as-synthesized
crude silane .
Table S1. Triethoxysilane loadings on SPNs.a
Coated silane Quantity used Silane loading
(mmol)
(mmol/g SPN)
1
2
1.0
1.0
0.23
0.34
3
1.0
0.79
4
1.0
0.16
5
6
7
1.0
0.5
0.4
0.31
0.23b
0.27
8
9
10
1.0
0.5
1.0
0.27
0.13c
0.15
aLoadings determined by sulfur elemental analysis.
bSilane loading assuming 94% of the SPN sulfur content is from
the functional silane and the rest from MPTES.
cSilane loading assuming 90% of the SPN sulfur content is from
the functional silane and the rest from MPTES.
S22

9.2- FT-IR spectroscopic analysis of silane-coated SPNs. FT-IR spectra of silane-coated SPNs pressed into KBr pellets were
obtained to confirm that that silanes had been immobilized on the particle surfaces. The figures shown below depict overlaid FT-IR
spectra of the pure silanes, silane-coated SPNs, oleic acid-coated SPNs, and bare magnetite SPNs. The spectra verify that all of the
triethoxysilanes 1–10 were successfully immobilized onto the surface of oleic-acid coated SPNs. A key indication that silanes have
been covalently immobilized on the nanoparticle surface is the presence of a new Si-O-Si stretching vibration between 1060 and
1140 cm-1.
3.0
3.0
2.5
2.5
2.0
2.0
1.5
1.5
1.0
1.0
0.5
0.5
PEG silane (1)
PEG coated SPN
Bare SPNs
Oleic acid coated SPN
Thiazole silane (2)
Thiazole coated SPN
Bare SPNs
Oleic acid coated SPNs
0.0
0.0
4000
3500
3000
2500
2000
)
1500
1000
500
4000
3500
3000
2500
2000
)
1500
1000
500
ṽ (cm-1
ṽ (cm-1
S23

3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
3.0
2.5
2.0
1.5
1.0
0.5
0.0
Acetal silane (3)
Acetal coated SPN
Bare SPNs
Oleic acid coated SPN
tert-Butyl ester silane (4)
tert-Butyl ester coated SPN
Bare SPNs
Oleic acid coated SPNs
4000
3500
3000
2500
2000
)
1500
1000
500
4000
3500
3000
2500
2000
)
1500
1000
500
ṽ (cm-1
ṽ (cm-1
S24

3.0
2.5
2.0
1.5
1.0
0.5
0.0
3.0
2.5
2.0
1.5
1.0
0.5
0.0
3.0
2.5
2.0
1.5
1.0
0.5
0.0
Proline silane (6)
Proline coated SPN
Bare SPNs
Oleic acid coated SPN
Quinuclidine silane (7)
Quinuclidine coated SPN
Bare SPNs
Oleic acid coated SPN
Thiourea silane (5)
Thiourea coated SPN
Bare SPNs
Oleic acid coated SPNs
4000
3500
3000
2500
2000
)
1500
1000
500
4000
3500
3000
2500
2000
)
1500
1000
500
4000
3500
3000
2500
2000
)
1500
1000
500
ṽ (cm-1
ṽ (cm-1
ṽ (cm-1
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
2.5
2.0
1.5
1.0
0.5
0.0
Quinine silane (8)
Quinine coated SPN
Bare SPNs
Oleic acid coated SPN
NTA silane (9)
NTA coated SPN
Bare SPNs
Oleic acid coated SPNs
Tetra-
Tetra-
O
O
-acylglucose silane (10)
-acylglucose coated SPN
Bare SPNs
Oleic acid coated SPNs
4000
3500
3000
2500
2000
)
1500 1000
500
4000
3500
3000
2500
2000
)
1500
1000
500
4000
3500
3000
2500
2000
)
1500 1000 500
ṽ (cm-1
ṽ (cm-1
ṽ (cm-1
S25

9.3- Magnetic properties of SPNs. The magnetic properties of the synthesized SPNs were measured at R.T. on a supercritical
quantum interference device (SQUID). Figure S3 shows magnetic hysteresis curves for all of the SPNs: the bare magnetite, the oleic
acid-coated particles, and the silane-modified SPNs. All of the particles exhibit low coercivity, <20 Oe, indicating that they are
superparamagnetic. Both the coated and uncoated particles have excellent saturation magnetizations, >34 emu/g, which means they
are strongly attracted to magnetic fields produced by standard rare-earth magnets.
60
Bare magnetite SPNs
Oleic acid SPNs
PEG SPNs
Thiazole SPNs
40
Diethyl acetal SPNs
tert-Butyl ester SPNs
Thiourea SPNs
Proline SPNs
Quinuclidine SPNs
Quinine SPNs
20
NTA SPNs
Tetra-O-acylglucose SPNs
0
-20
-40
-60
-10000
-5000
0
5000
10000
Applied Field (Oe)
Figure S3. Magnetic hysteresis curves of all synthesized SPNs.
S26

9.4- Transmission electron microscopy (TEM) of SPNs. The TEM images in Figure S4 show silane-coated SPNs ranging in size
from ~10 to 25 nm. This polydispersity is expected from the protocol that was used to prepare these Fe3O4 nanoparticles. Single
particles, clusters and large aggregates are typically present. We did not systematically investigate the reasons for the varying extent of
particle aggregation, because many factors can influence this process and some are interdependent. These factors include: a) the
composition of the surface coating; b) the surface coverage of the silane coating; c) the uniformity of silane coating; d) interactions
between the particles, which are solvent-dependent; e) the dispersing solvent; and f) the cleanliness and surface charge of the carbon
grids onto which the particle suspensions are deposited for TEM analysis.
S27

a)
d)
g)
c)
f)
i)
b)
e)
h)
80 nm
80 nm
80 nm
80 nm
60 nm
80 nm
60 nm
80 nm
80 nm
j)
80 nm
Figure S4. TEM images of a) PEG SPNs, 1, b) thiazole SPNs, 2, c) aectal SPNs, 3, d) tert-butyl ester SPNs, 4, e) thiourea SPNs, 5, f) proline SPNs, 6, g)
quinuclidine SPNs, 7, h) quinine SPNs, 8, i) NTA SPNs, 9, j) tetra-O-acylglucose, 10, SPNs.
S28

10. 1H and 13CNMR spectra of synthesized compounds.
Shown below are 1HNMR and 13CNMR spectra of the synthesized compounds. Note that 13CNMR spectra obtained with our 400 MHz
spectrometer sometimes showed a significant amount of noise at ~118 and 129 ppm. Although this noise may look like one or more
real spectral features, it is an artifact produced by the spectrometer, and cannot be corrected or compensated for, due to the
instrument’s age. These artifacts, denoted with asterisks (*) in the 13CNMR spectra, are more noticeable when the signal-to-noise ratio
is low. We have verified that the features are not assignable to vinyl carbons from unreacted alkenes by observing that 1HNMR spectra
of the same samples usually have extremely weak or no signals from the vinyl protons. Most importantly, high resolution mass spectra
of the synthesized compounds confirm their identities.
S29

2,5,8,11,14-Pentaoxaheptadec-16-ene
NAME
June1-2010
151
EXPNO
PROCNO
Date_
1
20100601
13.58
Time
INSTRUM
arx400
O
O
O
PROBHD 5 mm QNP 1H
O
O
PULPROG
TD
zg30
65536
SOLVENT
NS
CDCl3
8
0
DS
SWH
FIDRES
AQ
8064.516 Hz
0.123055 Hz
4.0632820 sec
512
62.000 usec
88.57 usec
300.0 K
2.00000000 sec
7.50 usec
400.1324008 MHz
RG
DW
DE
TE
D1
P1
SFO1
NUCLEUS
SI
1H
65536
SF
400.1300173 MHz
WDW
SSB
LB
EM
0
0.30 Hz
0
GB
PC
1.00
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
ppm
S30