COMMUNICATION
2. Energy dispersive X-ray spectroscopy (EDX)
4.1 Temperature-Dependent 1 H NMR Spectroscopy
1H NMR measurements of i were carried out by using a Bruker DRX 300 MHz spectrometer. The solvent used was CD2Cl2 in all cases. Figure S3 shows the results.
The first spectrum (from bottom to top) was recorded at room temperature using a sample prepared with B under exclusion of daylight.
The next three spectra were recorded at different temperatures from a batch produced from precursor A under exclusion of daylight. I was dissolved at 273 K, and the spectra were subsequently recorded with rising temperature. THF and water impurities are visible. Three main signals at 1.27 ppm, 2.21 ppm and 2.71 ppm can be attributed to the organic ligand R1 in B, which indicates a formation of B after dissolving i. This is consistent with the isolation of crystals of B alongside crystals of 1.
The fourth spectrum shows a spectrum of i produced from precursor A at room temperature after exposure to daylight for 4 hours. The fifths and topmost spectrum shows the same sample after exposure to daylight for 24 hours. This lead to the rise of signals at 1.87 ppm, 2.10 ppm and 2.12 ppm, most likely intermediates towards decomposition to binary selenides and elements like 1.
In conclusion, neither variation of the reactants (A versus B) nor variation of the temperature lead to a disparity in the spectra. Light irradiation leads to the occurrence of new signals, but eventually to decomposition of the sample: if stored for 48 hours under daylight, one observes the precipitation of selenides and metal elements.
Figure S3. 1H NMR spectra of i in CD2Cl2.
S5
Crystals of 2 were dissolved and 1H NMR experiments were carried out. The resulting spectrum is shown in Figure S4. However, the obtained signals do not seems to correspond to a single set corresponding to the R1 ligand, typically found around 1.3 ppm, 2.2 ppm and 2.7 ppm with integral ratios of 6 to 3 to 2, thus pointing to an equilibrium of various species in solution.
Figure S4. 1H NMR spectra of 2 in CD2Cl2.
S6
Crystals of 3 were dissolved in CD2Cl2 to record NMR spectra. The solution turned from golden yellow to orange red within 20 seconds. The resulting 1H NMR spectrum is shown in Figure S5. The individual signals could not be identified, but three ranges (ca. 1.0 to 1.4 ppm, 1.7 to 2.1 ppm, and 2.2 to 2.7 ppm) show signals that can be attributed to the organic ligand, which is typically used in our chemistry. Additional, newly arising signals at 5.60 and 5.68 ppm hint towards the presence of hydrazone groups and thus a successful condensation reaction between the ketone in R1 and hydrazine hydrate.
Figure S5. 1H NMR spectrum of a solution of 3 in CD2Cl2.
S7 4.2 MAS NMR spectroscopy
All solid-state NMR spectra were acquired on a Bruker Avance-II spectrometer operating at a B0 field of 7.4 T. 77Se ( 0 = 57.24 MHz) and 119Sn ( 0 = 111.89 MHz) high-resolution spectra were acquired with a ramped cross-polarization (CP)[1]
experiment where the nutation frequency nut on the proton channel was varied linearly by 30%. The samples were spun at 10 and 12.5 kHz in a 4 mm MAS triple resonance probe (Bruker), respectively. The sample was packed in a glove box and handled strictly inert gas atmosphere. The corresponding nut on the X channel and the contact time were adjusted to 70 kHz and 3.0 ms. Proton broadband decoupling with spinal-64[2] was applied during acquisition with a nutation frequency of 50 kHz. The 77Se and
119Sn spectra are referenced with respect to Me2Se and SnMe4 using secondary standards.
Figure S6. 77Se MAS NMR spectrum of i at spinning speeds of 10 kHz and 12.5 kHz. Three chemically different Se sites are detected.
S8
Figure S7. 119Sn MAS NMR spectrum of i. Two chemically different Se sites could be detected.
S9
5 Details of the X-ray diffraction measurements and refinements 5.1 Methods
All single-crystal X-ray diffraction studies were performed on Stoe IPDS2/2T diffractometers at 100 K, using a Mo-K X-ray source (λ = 0.71073 Å). The structures were solved by direct methods in SHELXS97 and refined by full-matrix-least-squares refinement against F2 in and SHELX2013.[1] Methyl and methylene hydrogen atoms were added assuming ideal geometry on their carbon parent atom, with Ueq = nUeq
(parent atom), n = 1.2 for methylene and 1.5 for methyl groups. All structures are shown with thermal ellipsoids drawn at 50% probability. Hydrogen atoms are omitted for clarity in the structure figures. More detailed crystallographic data are available in Table S2 and from the CIF.
Table S2. Crystallographic data and refinement results of 1 and 2.
15.25 DCM 22 DCM
Empirical formula C77.3H139.5O12Cl10.5Se25Sn12Ag14 C62H78Cl6P2Se8Sn6Ag2
Fw / gmol–1 6297.32 2721.44
Crystal color and shape red block colorless block
Crystal size / mm3 0.108×0.105×0.078 0.454×0.195×0.167
Crystal system Monoclinic triclinic
Space group P21/n P
a / Å 17.7232(6) 12.9934(4)
b / Å 19.5772(4) 14.0644(5)
c / Å 22.4737(8) 14.1006(5)
/ ° 90 90.145(3)
/ ° 92.021(3) 112.437(3)
/ ° 90 116.178(3)
V / Å3 7792.9(4) 2091.6(2)
Z 2 1
calcd / gcm–3 2.76 2.161
(Mo K) / mm–1 9.655 5.969
Absorption correction type Numerical Numerical
Min. / max. transmission 0.3486 / 0.5469 0.1936 / 0.4646
2 range / deg 2.76 / 53.69 3.298 / 58.506
No. of measured reflns 93528 43266
R(int) 0.2081 0.1231
Indep. Reflns 16539 11250
Indep. Reflns (I > 2(I)) 8342 9881
No. of parameters 704 412
R1 (I > 2(I)) / wR2 (all data) 0.0605 / 0.1175 0.0282 / 0.0663
S (all data) 0.841 0.997
Max. peak / hole / e–Å3 2.63 / –1.16 1.04/ –1.50
CCDC number CCDC 1562670 CCDC 1562671
S10 5.2 Crystal structure of 1
The highest peak of residual electron density on the difference Fourier map (2.63 e–
·Å–3) is found 1.063 Å apart from Sn1 on the bond between Sn1 and Se11. The atomic positions of three molecules of CH2Cl2 were found in the asymmetric unit, one being only partially occupied with a freely refined site occupancy of 0.63. A cutout of the crystal structure of 1 is shown in Figure S8. Some structural parameters are given in Table S3.
Figure S8. Cutout of the crystal structure of 1 viewed along the [101] axis. 1 crystallizes in the monoclinic space group P21/n.
In a simplified manner, the structure can be viewed as a body centered cubic packing of 1. Intramolecular hydrogen bonds can be formulated between the O1 and C36 sites with a donor–acceptor distance of 3.20(2) Å and a C−H···O angle of 122.77°.
S11
Table S3. Selected structural parameters of 1. a = −x + 2, −y + 1, −z + 2
Parameter Value [Å / °] Parameter Value [Å / °] Parameter Value [Å / °]
Se1–Ag1 2.640(1) Sn2–Se2 2.512(2) Ag2···Ag4 3.236(2) Se1–Ag2 2.692(1) Sn2–Se8 2.598(2) Ag2···Ag5 2.974(2) Se1–Ag3 2.705(1) Sn2–Se11 2.547(2) Ag2···Ag6a 3.019(2) Se8–Ag1 2.633(2) Sn2–C7 2.20(2) Ag2···Ag7a 2.954(2) Se9a–Ag2 2.677(2) Sn2···O2 2.76(1) Ag3···Ag4a 2.949(2) Se10–Ag3 2.678(2) Sn3–Se3 2.508(2) Ag3···Ag5 3.034(2) Ag4–Se2 2.643(2) Sn3–Se10 2.601(2) Ag3···Ag6 2.914(1) Ag4–Se5 2.623(2) Sn3–Se13 2.541(2) Ag3···Ag7a 3.003(2) Ag4–Se7a 2.649(2) Sn3–C13 2.16(2) Ag1–Se1–Ag2 91.11(4) Ag5–Se2 2.633(2) Sn3···O3 2.71(1) Ag1–Se1–Ag2a 88.89(4) Ag5–Se3 2.632(2) Sn4–Se7 2.520(2) Ag1–Se1–Ag3 92.47(3) Ag5–Se6 2.612(2) Sn4–Se10 2.624(2) Ag1–Se1–Ag3a 87.53(3) Ag6–Se3 2.647(2) Sn4–Se13 2.555(2) Se1–Ag1–Se8 170.61(6) Ag6–Se4 2.634(2) Sn4–C19 2.22(2) Se1–Ag2–Se9a 171.50(6) Ag6–Se7 2.619(2) Sn4···O4 2.56(1) Se1–Ag3–Se10 175.28(7) Ag7–Se4 2.625(2) Sn5–Se6 2.522(2) Se5–Ag4–Se2 128.65(6) Ag7–Se5 2.628(2) Sn5–Se9 2.647(2) Se5–Ag4–Se7a 119.76(7) Ag7–Se6a 2.636(2) Sn5–Se12 2.518(2) Se7a–Ag4–Se2 111.29(6) Se2–Sn2 2.512(2) Sn5–C25 2.19(2) Se2–Ag5–Se3 116.86(6) Se3–Sn3 2.508(2) Sn5···O5 2.62(1) Se2–Ag5–Se6 122.75(6) Se4–Sn6 2.525(2) Sn6–Se4 2.525(2) Se3–Ag5–Se6 119.32(6) Se5–Sn1 2.518(2) Sn6–Se9 2.610(2) Se3–Ag6–Se4 112.22(6) Se6–Sn5 2.522(2) Sn6–Se12 2.521(2) Se3–Ag6–Se7 128.70(6) Se7–Sn4 2.520(2) Sn6–C31 2.21(1) Se4–Ag6–Se7 118.44(7) Sn1–Se5 2.518(2) Sn6···O6 2.68(1) Se4–Ag7–Se5 120.29(7) Sn1–Se8 2.627(2) Ag1···Ag4 2.894(2) Se4–Ag7–Se6a 126.19(7) Sn1–Se11 2.564(2) Ag1···Ag5 3.009(2) Se5–Ag7–Se6a 113.31(6) Sn1–C1 2.23(2) Ag1···Ag6 3.031(2)
Sn1···O1 2.56(1) Ag1···Ag7 3.000(2)
S12 5.3 Crystal structure of 2
The highest peak of residual electron density on the difference Fourier map (1.04 e–
·Å–3) is found 98.9 pm apart from Sn2 on the bond between Sn2 and Se3. Two molecules of CH2Cl2 were found in the asymmetric unit. A cutout of the crystal structure of 2 is shown in Figure S9. Some structural parameters are given in Table S4.
Figure S9. Cutout of the crystal structure of 2 viewed along the crystallographic a axis. 2 crystallizes in the triclinic space group P.
Table S4. Selected structural parameters of 2. A = −x + 2, −y + 1, −z + 2.
Parameter Value [Å / °] Parameter Value [Å / °] Parameter Value [Å / °]
Sn1–Ag1 2.7246(5) Ag1–Se2a 2.7507(4) Se2–Sn3–O2 172.35(5) Sn1–Cl1 2.4729(7) Ag1–Se4 2.6590(4) Sn1–Se1–Sn2 93.22(1) Sn1–Se1 2.5941(5) Ag1–P1 2.4687(6) Sn2–Se2–Sn3 84.13(1) Sn1–Se4a 2.6441(4) Ag1–Sn1–Se1 141.80(1) Sn2–Se2–Ag1 122.27(1) Sn2–Se1 2.5098(4) Ag1–Sn1–Se4a 113.95(1) Sn3–Se2–Ag1 112.25(1) Sn2–Se2 2.6381(4) Ag1–Sn1–Cl1 110.90(2) Sn2–Se3–Sn3 87.43(1) Sn2–Se3 2.5379(5) Se4a–Sn1–Se1 94.30(1) Sn1–Se4–Sn3 96.57(1) Sn2··O1 2.470(2) Se3–Sn2–Se1 115.96(1) Sn1–Se4–Ag1 89.92(1) Sn2–C1 2.182(4) Se3–Sn2–C1 124.14(8) Sn3–Se4–Ag1 99.27(1) Sn3–Se2 2.5823(4) C1–Sn2–Se1 109.89(8) Sn1–Ag1–Se2a 90.28(1) Sn3–Se3 2.5235(4) Se2–Sn2–O1 165.35(6) Sn1–Ag1–Se4 120.02(1) Sn3–Se4 2.5345(5) Se3–Sn3–Se4 112.73(1) Se4–Ag1–Se2a 110.68(1) Sn3··O2 2.775(2) Se3–Sn3–C7 115.44(8) Sn1–Ag1–P1 120.45(2) Sn3–C7 2.193(3) C7–Sn3–Se4 114.95(8)
S13 5.4 Preliminary crystal structure data of 3
The single-crystal X-ray diffraction of the crystals of 3 yielded data with subpar quality (Rint = 0.2017, R1 = 0.2625, 2max = 26.508°). We decided to use the isotropically refined heavy atom inorganic core as the basis for a preliminary discussion of the topology 3, which does not intend to be a discussion of its actual molecular structure.
The arrangement of the discussed cluster fragments in the crystal structure is shown in Figure S10.
Figure S10. Cutout of the preliminary crystal structure of 3.
S14 6. Quantum Chemical Studies