Aviii hd400 spectrometer

GeCl₂·dioxane,
Sn(OTf)₂, Pb(OTf)₂, [9]aneS₃, [12]aneS₄, and [24]aneS₈ were obtained from Sigma-Aldrich.
The metal triflates were
dried by gentle heating in vacuo for 2–3 h prior to use. TMSOTf
(Sigma-Aldrich) was distilled prior to use. All reactions were conducted
using Schlenk, vacuum line, and glovebox techniques and under a dry
dinitrogen atmosphere. CH₂Cl₂ and MeCN were
dried by distillation from CaH₂ and n-hexane
from Na and stored over activated molecular sieves. NMR solvents were
also stored over 4 Å sieves.
IR spectra were recorded as
Nujol mulls between CsI plates using
a PerkinElmer Spectrum 100 spectrometer over the range of 4000–200
cm^–1. NMR spectra were recorded using a Bruker AVII
400 or AVIII HD400 spectrometer. ¹H and ¹³C{¹H} NMR spectra were referenced to residual solvent resonances, ¹⁹F{¹H} NMR spectra to external CFCl₃, and ¹¹⁹Sn{¹H} NMR spectra to SnMe₄. Microanalytical measurements were performed by Medac Ltd. For ESI⁺, mass spectrometry samples were diluted into acetonitrile
to an approximate concentration of 10 μg/mL. The solution was
infused using a syringe driver at a constant flow rate of 3 μL/min.
High-resolution positive ion electrospray mass spectra were recorded
using a MaXis (Bruker Daltonics, Bremen, Germany) time of flight mass
spectrometer. Data were processed using Bruker Compass DataAnalysis
software 1.3.

First, spider silk was reeled manually onto a glass ring to create a web mesh and a total of three such rings were prepared. In the first two silk sings, a few droplets (with a total volume of 5 µL) of either Microbacterium sp. or Novosphingobium sp. cultured in NFG broth were dripped by pipette onto spider silk mesh. In the third ring same amount of NFG broth was dripped on silk mesh to serve as a control. All three rings were then incubated at 28 °C for 24 h. After incubation, silk form the rings was collected, placed into Eppendorf, weighted, and proceeded to NMR operation. The ¹H NMR spectra were recorded using a Bruker AVIII HD 400 spectrometer. Chemical shifts were reported in ppm downfield from (CH₃)₄Si, and coupling constants (J) were given in Hertz. Spider silk samples (20 mg each) was mixed with D₂O and soaked in an Eppendorf tube for 15 min. Subsequently, 0.5 mL of the resulting D₂O solution was extracted from the tube and used for measurement and analysis.

Silicon halides, PMe₃, and Et₂P(CH₂)₂PEt₂ were
obtained from Strem, Alfa Aesar,
or Sigma-Aldrich and used as received. TMSOTf (Sigma-Aldrich) was
distilled prior to use. o-C₆H₄(PMe₂)₂ was made by the literature route.^{18 (link)} All reactions were conducted using Schlenk,
vacuum line, and glovebox techniques and under a dry dinitrogen atmosphere.
CH₂Cl₂ was dried by distillation from CaH₂ and n-hexane, n-pentane
and toluene from Na, and stored over activated molecular sieves. NMR
solvents were also stored over 4 Å sieves.
IR spectra were
recorded as Nujol mulls between CsI plates using
a Perkin Elmer Spectrum 100 spectrometer over the range of 4000–200
cm^–1. NMR spectra were recorded using a Bruker AVII
400 or AVIII HD400 spectrometer. ¹H NMR spectra were referenced
to residual solvent resonances,¹⁹F{¹H} NMR spectra
to external CFCl₃, ³¹P{¹H} NMR spectra
to aqueous 85% H₃PO₄, and ²⁹Si NMR
spectra to TMS. The latter used tris(2,2,6,6-tetramethyl-3,5-heptanedionato)chromium(III)
(TMD) as a relaxation agent. Microanalytical measurements were performed
by Medac Ltd.