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500 MHz spectrometer (operating at 99.3 MHz). All measurements
were performed at room temperature by using TMS as external
standard. MS (EI) spectra were recorded on an Agilent Technolo-
gies 5975C inert XL MSD with SIS Direct Insertion Probe. ESI and
APCI mass spectra were recorded on a Finnigan LCQ Deca (Ther-
moQuest). HRMS (ESI) spectra were recorded by using a micrOTOF
(Bruker Daltonics) and an Apollo “Ion Funnel” ESI-ion source. IR
spectra were recorded by using a Bruker Alpha Platinum ATR spec-
trometer. Elemental analysis data were obtained by using a Euro
EA by HEKAtech.
paper. These data can be obtained free of charge from The Cam-
request/cif.
Surface-tension measurements
Surface-tension measurements were performed on a Dataphysics
OCA20 system by using the pendant-drop method. All manipula-
tions were performed at room temperature. All data points are
mean values calculated by using the Dataphysics SCA 20 software
(DataPhysics Instruments GmbH, Filderstadt, Germany) from at
least 20 independent measurements. Contact-angle measurements
were performed on a Dataphysics (DataPhysics Instruments GmbH,
Filderstadt, Germany) contact angle system (OCA15+) by using
water, diiodomethane, and formamide as solvents with a drop
volume of 5 mL. Solvent properties of the three testing liquids used
for the calculation of the SFE can be found in the Supporting Infor-
mation. At least three different glass slides were used for contact-
angle determinations of each wetting liquid. On each slide, 7–
10 drops were deposited. For the determination of the equilibrium
structure of the liquid/solid/vapor interface, the sessile drop
method was used. For the neat solvents, surface tensions of 72.75
(water), 50.80 (diiodomethane), and 58.20 mJmÀ12 (formamide)
were used for further calculations.
X-Ray diffraction measurements
X-Ray diffraction measurements were performed on a Stoe IPDS2
or a BRUKER-AXS SMART APEX 2 CCD diffractometer by using
graphite monochromatized MoKa radiation. Essential details of the
crystal-data and structure refinement for 4b–e are summarized in
Table 4.
Table 4. Crystal data and structure refinement for 4b–e.[17,18]
4b
4c
4d
4e
formula
C5H14O3Si
148.24
C6H16O3Si C7H18O3Si
C8H20O3Si
192.33
formula weight
164.28
178.30
[gmolÀ1
T [K]
]
Surface free-energy calculations
100
95
100
100
In the van Oss or LWAB approach[34,35] the surface energy is ex-
pressed as sum of the apolar interactions, called Lifshitz–van der
Waals (gi, LW, includes London dispersion, Debye induction
(dipole-induced dipole), and Keesom orientation (dipole–dipole
forces)) and the polar Lewis acid/base (gi, AB, often due to hydro-
gen bonding) interactions according to Equation (1),[30] in which
gi,- is the electron donor and gi,+ the electron-acceptor compo-
nent of the energy of the phases i. The work of adhesion WH then
can be defined according to the Young–Dupre equation:[35] for a so-
lution of this equation and the determination of the surface-ten-
sion components of a solid, we employed diiodomethane (gL =
gL,LW), formamide (gL =gL,LW +gL,-), and water (gL =gL,LW +gL,+ +gL,À).
l [ꢂ]
crystal system
space group
unit-cell dimensions
0.71073
0.71073
0.71073
0.71073
monoclinic monoclinic monoclinic monoclinic
P21/c P21/c P21/c P21/c
a [ꢂ]
b [ꢂ]
c [ꢂ]
b [8]
V [ꢂ3]
Z
1calcd [mgmÀ13
m [mmÀ1
V range for data
collected [8]
11.1160(14) 11.657(6) 12.4316(10) 14.4406(8)
6.6685(8) 6.801(3) 6.6759(5) 6.5522(4)
12.3970(14) 12.249(8) 12.5082(9) 12.5218(7)
113.433(6) 99.79(4)
843.16(17) 957.0(9)
100.143(2) 108.684(2)
1021.86(13) 1122.35(11)
4
1.159
0.195
4
4
4
]
1.184
0.225
1.140
0.203
1.138
0.182
]
2.00–26.00 3.38–26.00 3.33–26.00 2.98–28.00
The substrates (glass slides and silicon wafers) were cleaned by
treatment with Caro’s acid, freshly prepared by carefully adding
H2O2 (33%) to H2SO4 (conc.) in a ratio 3:7. After 30 min, the slides
were rinsed three times with double distilled water and dried in
a stream of nitrogen before performing the coating experiments.
For the dip-coating experiments, solutions containing 0.02wt%
(glass slides) or 0.10 and 0.25 wt% (silicon wafers) of 4b–f in
double distilled water were prepared and used immediately. After
the dip-coating experiments (30 min), the substrates were dried for
24 h at 608C in a drying oven and after cooling, they were washed
with double distilled water.
unique reflections
parameters
goodness-of-fit on F2
R1 (obs. data)1
wR2 (all data)
1646
108
1.161
0.0644
0.1549
1883
118
1.138
0.0516
0.1361
1994
129
1.078
0.0370
0.1023
2684
122
1.038
0.0302
0.0840
The structures were solved by using direct methods (SHELXS-97)
and refined by full-matrix-least-squares techniques against F2
(SHELXL-97). The nonhydrogen atoms were refined with anisotrop-
ic displacement parameters without any constraints. The hydrogen
atoms of the OH groups are disordered over two sites. They were
refined with one common isotropic displacement parameter. The
bond lengths were fixed to 0.84 ꢂ and some restraints were ap-
plied to these H atoms. The H atoms of the CH2 groups were re-
fined with common isotropic displacement parameters for the H
atoms of the same group and idealized geometries with approxi-
mately tetrahedral angles and CÀH distances of 0.99 ꢂ. The H
atoms of the methyl groups were refined with common isotropic
displacement parameters for the H atoms of the same group and
idealized geometries with tetrahedral angles, enabling rotation
around the CÀC bond, and CÀH distances of 0.98 ꢂ. CCDC-972002
(4b), CCDC-766344 (4c), CCDC-972003 (4d), and CCDC-972004
(4e) contain the supplementary crystallographic data for this
Atomic force microscopy (AFM) images were recorded on a Nano-
scope V Multimode AFM (Veeco) by using silicon cantilevers TESP7
from Veeco Instruments with an average spring constant of
40 NmÀ1, tip radius of 8 nm, and resonance frequency of 320 kHz.
Image processing, analysis, and root mean-square roughness calcu-
lations were performed with WSxA freeware[44]
.
Synthesis
Synthesis of the tertiary trichlorosilanes 3b–f
The corresponding tertiary bromide 2a–f (1 equiv) was dissolved in
Et2O and slowly added to Mg turnings (1.1 equiv). Subsequently,
the obtained Grignard solution was slowly added by cannula to
Chem. Eur. J. 2014, 20, 1 – 7
5
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