Grzegorz Jędrzejczyk, Bruno Skoczeń, Iwona Justyniak, Janusz Lewiński. “Electrostatic preorganisation shapes a hypercoordination valley along the donor–acceptor bonding continuum.” ChemRxiv (). https://doi.org/10.26434/chemrxiv.15007776/v1

[Me₃Al(pyrazine)]ₙ
Identifier 1
¹H NMR (600 MHz, C₆D₆, 298 K) δ = 7.67 ppm (s, 4H, CAr–H), −0.33 (s, 9H, Al–CH₃)
¹³C NMR (151 MHz, C₆D₆, 298 K) δ = 143.8, −7.9 ppm
Single-crystal X-ray diffraction, coordination geometry N–Al–N = 174.8°; pyramidalisation angle θP approaches 0°; equivalent Al–N bonds = 2.277 Å
Single-crystal X-ray diffraction, crystal data CCDC 2559793; empirical formula: C₇H₁₃AlN₂; formula weight: 152.17; T = 100(2) K; λ = 1.54184 Å; monoclinic; space group C2/c; a = 11.3742(7) Å, α = 90°; b = 6.7616(4) Å, β = 99.285(5)°; c = 11.2642(7) Å, γ = 90°; V = 854.95(9) ų; Z = 4; calculated density = 1.182 Mg m⁻³; absorption coefficient = 1.499 mm⁻¹; F(000) = 328
Single-crystal X-ray diffraction, data collection and refinement θ = 7.649–69.953°; −9 ≤ h ≤ 13, −8 ≤ k ≤ 8, −13 ≤ l ≤ 13; reflections collected/unique: 2373/795 [R(int) = 0.0189]; completeness to θ = 67.684°: 100.0 %; full-matrix least-squares on F²; data/restraints/parameters: 795/0/49; goodness-of-fit on F²: 1.087; final R indices [I > 2σ(I)]: R1 = 0.0293, wR2 = 0.0752; R indices (all data): R1 = 0.0315, wR2 = 0.0770; largest diff. peak and hole: 0.262 and −0.197 e Å⁻³
Single-crystal X-ray molecular-structure images Image data were not transcribed
Main, pp. 7–8; SI, pp. 2, 8–9
(Me₃Al)₂(μ-pyrazine)
Identifier 2
Powder X-ray diffraction (Ni-filtered Cu Kα, Bragg–Brentano geometry, 2θ = 3–50°, step size 0.008°, protective dome) Experimental pattern image was not transcribed; broad amorphous background centred near 2θ ≈ 20° resulted from the protective dome
SI, pp. 3, 7
(Me₃Al)₂(μ-N₂-bipy)
Identifier 6
¹H NMR (600 MHz, C₆D₆, 298 K) δ = 8.33–8.30 (m, 4H, CAr–H), 6.90–6.87 ppm (m, 4H, CAr–H), −0.14 (s, 18H, Al–CH₃)
¹³C NMR (151 MHz, C₆D₆, 298 K) δ = 157.3, 149.4, 117.9, −7.5 ppm
Single-crystal X-ray diffraction, crystal data CCDC 2560816; empirical formula: C₁₆H₂₆Al₂N₄; formula weight: 328.37; T = 100(2) K; λ = 1.54184 Å; triclinic; space group P1̅; a = 12.6678(3) Å, α = 98.612(4)°; b = 12.7883(3) Å, β = 90.908(3)°; c = 16.8626(9) Å, γ = 118.419(2)°; V = 2363.50(16) ų; Z = 5; calculated density = 1.154 Mg m⁻³; absorption coefficient = 1.394 mm⁻¹; F(000) = 880
Single-crystal X-ray diffraction, data collection and refinement θ = 2.664–70.589°; −15 ≤ h ≤ 15, −15 ≤ k ≤ 15, −20 ≤ l ≤ 20; reflections collected/independent: 20685/8975 [R(int) = 0.0289]; completeness to θ = 67.684°: 99.8 %; full-matrix least-squares on F²; data/restraints/parameters: 8975/0/511; goodness-of-fit on F²: 1.033; final R indices [I > 2σ(I)]: R1 = 0.0713, wR2 = 0.2026; R indices (all data): R1 = 0.0844, wR2 = 0.2222; largest diff. peak and hole: 1.113 and −0.506 e Å⁻³
Single-crystal X-ray molecular-structure image Image data were not transcribed
SI, pp. 3, 8, 13
[(Me₃Al)₂(μ-N₂-bipy) · N₂-bipy]
Identifier 7
¹H NMR (600 MHz, C₆D₆, 298 K) δ = 8.51–8.42 (m, 8H, CAr–H), 7.15–7.06 ppm (m, 8H, CAr–H), −0.15 (s, 18H, Al–CH₃)
¹³C NMR (151 MHz, C₆D₆, 298 K) δ = 157.0, 150.8, 116.9, −7.5 ppm
Single-crystal X-ray diffraction, crystal data CCDC 2560817; empirical formula: C₂₆H₃₆Al₂N₈; formula weight: 514.59; T = 100(2) K; λ = 1.54184 Å; triclinic; space group P1̅; a = 7.7942(3) Å, α = 94.509(3)°; b = 9.1195(3) Å, β = 106.049(4)°; c = 10.6335(5) Å, γ = 96.736(3)°; V = 716.45(5) ų; Z = 1; calculated density = 1.193 Mg m⁻³; absorption coefficient = 1.142 mm⁻¹; F(000) = 274
Single-crystal X-ray diffraction, data collection and refinement θ = 4.356–70.303°; −9 ≤ h ≤ 8, −11 ≤ k ≤ 11, −12 ≤ l ≤ 11; reflections collected/independent: 4479/2671 [R(int) = 0.0184]; completeness to θ = 67.684°: 99.3 %; full-matrix least-squares on F²; data/restraints/parameters: 2671/0/163; goodness-of-fit on F²: 0.997; final R indices [I > 2σ(I)]: R1 = 0.0440, wR2 = 0.1253; R indices (all data): R1 = 0.0452, wR2 = 0.1265; largest diff. peak and hole: 0.417 and −0.415 e Å⁻³
Single-crystal X-ray molecular-structure image Image data were not transcribed
SI, pp. 3, 8, 14
[Me₃Al(DABCO)]ₙ
Identifier 3
¹H NMR (600 MHz, C₆D₆, 298 K) δ = 2.16 (s, 12H, N–CH₂CH₂–N), −0.55 (s, 9H, Al–CH₃) ppm
¹³C NMR (151 MHz, C₆D₆, 298 K) δ = 45.4, −9.6 ppm
Single-crystal X-ray diffraction, coordination geometry N–Al–N = 179.3°; θP ≈ 0°; Al–N distance = 2.379 Å
Single-crystal X-ray diffraction, crystal data CCDC 2559794; empirical formula: C₉H₂₁AlN₂; formula weight: 184.26; T = 100(2) K; λ = 0.71073 Å; orthorhombic; space group Pmmn; a = 7.3812(5) Å, α = 90°; b = 10.6670(6) Å, β = 90°; c = 6.5322(4) Å, γ = 90°; V = 514.31(6) ų; Z = 2; calculated density = 1.190 Mg m⁻³; absorption coefficient = 0.150 mm⁻¹; F(000) = 204
Single-crystal X-ray diffraction, data collection and refinement θ = 3.119–29.674°; −9 ≤ h ≤ 9, −14 ≤ k ≤ 12, −8 ≤ l ≤ 8; reflections collected: 3753; independent reflections: 762 [R(int) = 0.0218]; completeness to θ = 25.242°: 99.8 %; full-matrix least-squares on F²; data/restraints/parameters: 762/0/38; goodness-of-fit on F²: 1.095; final R indices [I > 2σ(I)]: R1 = 0.0384, wR2 = 0.1137; R indices (all data): R1 = 0.0410, wR2 = 0.1157; largest diff. peak and hole: 0.464 and −0.191 e Å⁻³
Single-crystal X-ray molecular-structure images Image data were not transcribed
Main, pp. 7–8; SI, pp. 4, 8, 10
[Me₃Al(dithiane)]ₙ
Identifier 4
¹H NMR (600 MHz, C₆D₆, 298 K) δ = 2.16 (s, 8H, S–CH₂CH₂–S), −0.40 (s, 9H, Al–CH₃) ppm
¹³C NMR (151 MHz, C₆D₆, 298 K) δ = 28.4, −9.0 ppm
Single-crystal X-ray diffraction, coordination geometry Primary Al–S bond = 2.553 Å; secondary Al···S approach = 3.359 Å; S–Al–S = 176.0°; θP = 6.46°
Single-crystal X-ray diffraction, crystal data CCDC 2559796; empirical formula: C₇H₁₇AlS₂; formula weight: 192.30; T = 100(2) K; λ = 1.54184 Å; triclinic; space group P1̅; a = 7.610(2) Å, α = 68.498(19)°; b = 8.726(2) Å, β = 87.295(19)°; c = 9.4902(17) Å, γ = 64.90(3)°; V = 526.6(3) ų; Z = 2; calculated density = 1.213 Mg m⁻³; absorption coefficient = 4.862 mm⁻¹; F(000) = 208
Single-crystal X-ray diffraction, data collection and refinement θ = 5.051–70.594°; −9 ≤ h ≤ 8, −10 ≤ k ≤ 9, −10 ≤ l ≤ 11; reflections collected: 2513; independent reflections: 1726 [R(int) = 0.0534]; completeness to θ = 67.684°: 87.5 %; full-matrix least-squares on F²; data/restraints/parameters: 1726/0/94; goodness-of-fit on F²: 1.002; final R indices [I > 2σ(I)]: R1 = 0.0688, wR2 = 0.1973; R indices (all data): R1 = 0.0861, wR2 = 0.2118; largest diff. peak and hole: 0.651 and −0.737 e Å⁻³
Single-crystal X-ray molecular-structure images Image data were not transcribed
Main, pp. 7–8; SI, pp. 5, 8, 11
(Me₃Al)₂(μ-dithiane)
Identifier 5
¹H NMR (600 MHz, C₆D₆, 298 K) δ = 2.07 (s, 8H, S–CH₂CH₂–S), −0.41(s, 18H, Al–CH₃) ppm
¹³C NMR (151 MHz, C₆D₆, 298 K) δ = 28.2, −8.7 ppm
Single-crystal X-ray diffraction, coordination geometry Equivalent Al–S bonds = 2.485 Å
Single-crystal X-ray diffraction, crystal data CCDC 2559795; empirical formula: C₁₀H₂₆Al₂S₂; formula weight: 264.39; T = 100(2) K; λ = 0.71073 Å; triclinic; space group P1̅; a = 8.3883(3) Å, α = 96.483(4)°; b = 9.0324(4) Å, β = 100.144(4)°; c = 11.0576(5) Å, γ = 90.666(4)°; V = 819.00(6) ų; Z = 2; calculated density = 1.072 Mg m⁻³; absorption coefficient = 0.404 mm⁻¹; F(000) = 288
Single-crystal X-ray diffraction, data collection and refinement θ = 2.270–29.640°; −10 ≤ h ≤ 8, −12 ≤ k ≤ 8, −13 ≤ l ≤ 15; reflections collected: 6679; independent reflections: 3966 [R(int) = 0.0211]; completeness to θ = 25.242°: 99.8 %; full-matrix least-squares on F²; data/restraints/parameters: 3966/0/133; goodness-of-fit on F²: 1.046; final R indices [I > 2σ(I)]: R1 = 0.0308, wR2 = 0.0795; R indices (all data): R1 = 0.0366, wR2 = 0.0832; largest diff. peak and hole: 0.314 and −0.301 e Å⁻³
Single-crystal X-ray molecular-structure images Image data were not transcribed
Main, pp. 7, 9; SI, pp. 5, 8, 12
(Me₃Al)₂(μ-C₂H₄-bipy)
Powder X-ray diffraction (Ni-filtered Cu Kα, Bragg–Brentano geometry, 2θ = 3–50°, step size 0.008°, protective dome) Experimental pattern image was not transcribed; broad amorphous background centred near 2θ ≈ 20° resulted from the protective dome
SI, pp. 7–8
Me₃Al + CH₃-py mixtures with differing Al-to-ligand ratios
¹H NMR (600 MHz, THF-d₈, 298 K) Minor changes were observed; image data were not transcribed
²⁷Al NMR (156 MHz, THF-d₈, 298 K) No significant differences between the spectra; broad resonances at ca. 70 and −10 ppm originate from the NMR probe and the sample tube; image data were not transcribed