The solid-state CP/MAS 13C NMR spectra were recorded on a Bruker AVIII-400 MHz with a 4 mm HR MAS BL4 probe. The spectroscopy of cellulose samples for solid state CP-MAS (cross-polarisation, magic anglespinning) 13C NMR spectroscopy was obtained on a Bruker AVIII spectrometer (Bruker, Germany) and the span rate of the 4 mm rotor was 12 kHZ for the test. The acquisition time was 0.0127 s, and the recycle delay was 2.0 s.
Aviii 400 mhz
Manufactured by Bruker
Sourced in Germany
The AVIII 400 MHz is a nuclear magnetic resonance (NMR) spectrometer designed for analytical and research applications. It operates at a frequency of 400 MHz and is capable of performing various NMR experiments to analyze the structure and properties of chemical compounds.
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Lab products found in correlation
Aviii spectrometer, by Bruker (1 mentions)
Avance 3 hd 400, by Bruker (1 mentions)
600 mhz spectrometer, by Bruker (1 mentions)
Solarix system, by Bruker (1 mentions)
M 560, by Büchi (1 mentions)
Ir prestige 21 spectrometer, by Shimadzu (1 mentions)
Rf 5301pc spectrofluorophotometer, by Shimadzu (1 mentions)
Polystyrene standards, by Agilent Technologies (1 mentions)
J 1500 circular dichroism spectrometer, by Jasco (1 mentions)
Aviii 600 mhz spectrometer, by Bruker (1 mentions)
Av 500 mhz, by Bruker (1 mentions)
Ri detector, by Shimadzu (1 mentions)
Lambda 25, by PerkinElmer (1 mentions)
12 protocols using aviii 400 mhz
1
Solid-State 13C NMR Spectroscopy of Cellulose
2
Synthesis and Characterization of Organic Compounds
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Starting materials and solvents were purchased from commercial supplier without further purification. All oxygen-sensitive or water-sensitive reactions were carried out under nitrogen atmosphere. All reactions were monitored by TLC on 0.25 mm silica gel plate (HSGF254) and observed under 254 nm UV lamp. Compounds were subjected to column chromatography using commercial silica gel (200–300 mesh, Merck, Darmstadt, Germany) through medium-low pressure preparative chromatograph (Yamazen Co., Osaka, Japan). 1H NMR and 13 C NMR spectra were recorded on Bruker AVIII 400 MHZ using deuterated dimethyl sulfoxide (DMSO-d6) or deuterated chloroform (CDCl3). The chemical shift unit was ppm and the internal standard was tetramethylsilane (TMS). The precise molecular weight was determined by Waters ZQ4000 mass spectrometer (Waters Co., Milford, MA) and obtained by positive and negative ion mode scanning using electrospray ionisation (ESI) source.
3
Catalytic Activation of Iridium Complexes
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Solutions containing
the precatalyst1 with either 4-AP or 4-MP in methanol-d4 or protio methanol formed
the unactivated catalyst [Ir(COD)(IMes)(substrate)]Cl. A 0.6 mL aliquot
of this initial solution was added to a 5 mm NMR tube equipped with
a Young’s tap and degassed following the sample preparation
procedure described above. When4-MP was used as the
substrate, peaks corresponding to the precatalyst1 were
observed in the prepared solution and were quantified by 1H NMR at 400 MHz as contributing 15% of the signal, suggesting 85%
of1 had converted to the unactivated catalyst [Ir(COD)(IMes)(4-MP )]Cl at equilibrium. In contrast, no 1H NMR
peaks corresponding to1 were observed in the initial 1H NMR spectra for samples where 4-AP was used
as the substrate, suggesting full conversion to2 . When
the conversion of precatalyst1 into [Ir(COD)(IMes)(4-AP )]Cl 2 was monitored by 1H NMR
spectroscopy for a sample containing 5 mM of1 and 25
mM of4-AP in methanol-d4 at 280 K, the reaction took 14 min to reach completion.
To
monitor the formation of the active complex [Ir(H)2(IMes)(substrate)3]Cl (substrate =4-AP or 4-MP ),
H2 (4 bar absolute) was added to the headspace of the NMR
tube. The sample was shaken vigorously for around 5 s and inserted
into the NMR spectrometer (Bruker AVIII 400 MHz) at 298 K. A series
of 1H spectra were acquired over a period of 15.5 h (Figure S4 ).
the precatalyst
the unactivated catalyst [Ir(COD)(IMes)(substrate)]Cl. A 0.6 mL aliquot
of this initial solution was added to a 5 mm NMR tube equipped with
a Young’s tap and degassed following the sample preparation
procedure described above. When
substrate, peaks corresponding to the precatalyst
observed in the prepared solution and were quantified by 1H NMR at 400 MHz as contributing 15% of the signal, suggesting 85%
of
peaks corresponding to
as the substrate, suggesting full conversion to
the conversion of precatalyst
spectroscopy for a sample containing 5 mM of
mM of
To
monitor the formation of the active complex [Ir(H)2(IMes)(substrate)3]Cl (substrate =
H2 (4 bar absolute) was added to the headspace of the NMR
tube. The sample was shaken vigorously for around 5 s and inserted
into the NMR spectrometer (Bruker AVIII 400 MHz) at 298 K. A series
of 1H spectra were acquired over a period of 15.5 h (
4
NMR Analysis of Modified Wood Flour
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NMR (Bruker-AVIII-400 MHz, Aachen, Germany) was conducted on 160-mesh unmodified flour and modified wood flour, stirring DMSO-d6 evenly after adding 30 mg sample. In order to acquire 13C NMR spectra of modified wood samples, cross-polarization (CP) and magic angle spinning (MAS) methods were used at room temperature.
5
NMR Spectroscopy of GUF-14 Nanosheets
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Nuclear magnetic resonance
spectra were recorded on either a Bruker AVIII 400 MHz spectrometer
or a Bruker Avance III HD 400 spectrometer and referenced to residual
solvent peaks. Samples of bulk GUF-14 were prepared for analysis by
digestion in DMSO-d6/D2SO4. Samples of exfoliated GUF-14 nanosheets were prepared by
dissolving 10–15 mg in 1 mL of 1 M NaOH in D2O by
vigorous stirring for 24 h and filtered through cotton wool to remove
solid particles.
spectra were recorded on either a Bruker AVIII 400 MHz spectrometer
or a Bruker Avance III HD 400 spectrometer and referenced to residual
solvent peaks. Samples of bulk GUF-14 were prepared for analysis by
digestion in DMSO-d6/D2SO4. Samples of exfoliated GUF-14 nanosheets were prepared by
dissolving 10–15 mg in 1 mL of 1 M NaOH in D2O by
vigorous stirring for 24 h and filtered through cotton wool to remove
solid particles.
6
Acetylation Degree Quantification of PAMAM Dendrimers
7
Synthesis and Characterization of Novel Compounds
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All reagents and chemicals were purchased from Energy Chemical Co. Ltd. (Shanghai, China) and used without further purification. All solvents were dried and redistilled prior to use. The melting points were measured on a digital apparatus (M560 Buchi) and uncorrected. Nuclear magnetic resonance (NMR) spectra were performed on a Bruker AVIII 400 MHz instrument. Chemical shifts were measured relative to residual solvent peaks of chloroform-d as internal standards (7.26 ppm for 1H and 77.16 ppm for 13C). The following abbreviations were used to designate chemical shift multiplicities: s, singlet; d, doublet; t, triplet; m, multiplet. High-resolution mass spectra (HRMS) were recorded with a Thermo Scientific LTQ Orbitrap XL system or a Bruker solariX System.
8
Synthesis of Boron-Containing Heterocycles
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All reactions were performed under an atmosphere of dry argon using standard Schlenk or dry box techniques; solvents were dried over Na metal, K metal or CaH2, and were distilled under nitrogen. Reagents were of analytical grade, obtained from commercial suppliers and were used without further purification. 1H, 13C, 11B and 19F NMR spectra were recorded on a Bruker AVIII 400 MHz or Bruker Avance 500 MHz AV500 spectrometers at 298 K. Chemical shifts (δ) are given in p.p.m. Coupling constants J are given in Hz. In the 13C NMR spectra of compounds 3 –7 , presumable owing to the coupling with boron atoms, signals for the carbon atoms directly bonding to boron atoms could not be observed. Electrospray ionization (ESI) mass spectra were obtained at the Mass Spectrometry Laboratory at the Division of Chemistry and Biological Chemistry, Nanyang Technological University. Melting points were measured with OptiMelt (Stanford Research System). Fourier-transform infrared (FT-IR) spectra were recorded on a SHIMADZU IRPrestige-21 spectrometer using solid compound. Ultraviolet and fluorescence spectra were recorded on Cary 100 UV-Vis and SHIMADZU RF-5301PC spectrofluorophotometer, respectively.
9
Molecular Weight Characterization of Polymers
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All chemicals were purchased
from Sigma-Aldrich, TCI, and Oakwood Chemical and used as received
unless otherwise indicated. Gel-permeation chromatography (GPC) was
done using a Shimadzu pump coupled to a Shimadzu RI detector. Poly(styrene)
standards purchased from Agilent Technologies were used for column
calibration. Two GPCs with different eluents were used. One GPC ran
with a 0.03 M LiCl solution in N,N-dimethylformamide (DMF) as the eluent at a flow rate of 1
mL/min at 65 °C. A set of Polymer Standards columns (AM GPC gel,
10 μm, precolumn, 500 Å, and linear mixed bed) was used.
The second GPC ran with THF as the eluent at a flow rate of 1 mL/min
at ambient temperature. A set of Shodex GPC columns (KF-804 and KF-802.5)
was used. Mw, Mn, and Đ represent respectively the apparent
weight-average molecular weight, apparent number-average molecular
weight, and dispersity index. 1H NMR and 13C
NMR spectra were recorded at 25 °C on a Bruker AVIII400 MHz,
a Bruker AV 500 MHz, or a Bruker AVIII 600 MHz spectrometer. All chemical
shifts are reported in parts per million (ppm) with reference to solvent
residual peaks. Mass spectra of samples in methanol were acquired
with an Agilent 6224 Accurate-Mass TOF/LC/MS spectrometer. Circular
dichroism (CD) spectra and UV–vis spectra were obtained at
25 °C on a Jasco J-1500 circular dichroism spectrometer.
from Sigma-Aldrich, TCI, and Oakwood Chemical and used as received
unless otherwise indicated. Gel-permeation chromatography (GPC) was
done using a Shimadzu pump coupled to a Shimadzu RI detector. Poly(styrene)
standards purchased from Agilent Technologies were used for column
calibration. Two GPCs with different eluents were used. One GPC ran
with a 0.03 M LiCl solution in N,N-dimethylformamide (DMF) as the eluent at a flow rate of 1
mL/min at 65 °C. A set of Polymer Standards columns (AM GPC gel,
10 μm, precolumn, 500 Å, and linear mixed bed) was used.
The second GPC ran with THF as the eluent at a flow rate of 1 mL/min
at ambient temperature. A set of Shodex GPC columns (KF-804 and KF-802.5)
was used. Mw, Mn, and Đ represent respectively the apparent
weight-average molecular weight, apparent number-average molecular
weight, and dispersity index. 1H NMR and 13C
NMR spectra were recorded at 25 °C on a Bruker AVIII400 MHz,
a Bruker AV 500 MHz, or a Bruker AVIII 600 MHz spectrometer. All chemical
shifts are reported in parts per million (ppm) with reference to solvent
residual peaks. Mass spectra of samples in methanol were acquired
with an Agilent 6224 Accurate-Mass TOF/LC/MS spectrometer. Circular
dichroism (CD) spectra and UV–vis spectra were obtained at
25 °C on a Jasco J-1500 circular dichroism spectrometer.
10
Spectroscopic Characterization of Chemical Compounds
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All chemicals and reagents were used with HPLC grade without further puri cation. Melting point was observed with the open capillary melting point apparatus, hence uncorrected. IR spectra were recorded on ABB MB 3000 IR Spectrophotometer. NMR data were recorded on a Bruker AV(III)-400 MHz. All samples were analyzed in CDCl 3 . A visible double beam spectrophotometer (ELICO, SL 177) with 10 mm matched quartz cells has been used for routine absorbance measurements and spectral studies. UV-Visible double beam spectrophotometer (Cat No. SL 177, ELICO) with 10 mm matched quartz cells has been used for routine absorbance measurements and spectral studies. Melting point was observed with the open capillary melting point apparatus; hence uncorrected.
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