Compound characterization data

Yu Liu, Elias Alexopoulos, Shifaa S. A. Xec Daudo, Sukhdip Singh, Conrad A. P. Goodwin, Adam Brookfield, David Collison, Floriana Tuna, Yin-Shan Meng, Claire L. McMullin, Erli Lu, Fabrizio Ortu. “C–H activation and C–C coupling of arenes promoted by a room-temperature-stable barium amidinate electride.” ChemRxiv (2026). https://doi.org/10.26434/chemrxiv.15007674/v1

{(2,6-Dipp)N(H){C(Cy)}N(2,6-Dipp)}
Identifier	LH
¹H NMR (400 MHz, CDCl₃, 298 K)	δ / ppm = 1.00 (d, 6H, CH(CH₃)₂, ³JHH = 6.8 Hz), 1.03−1.12 (m, 2H, Cy-CH₂), 1.22 (d, 6H, CH(CH₃)₂, ³JHH = 6.7 Hz), 1.29 (d, 6H, CH(CH₃)₂, ³JHH = 6.9 Hz), 1.32 (d, 6H, CH(CH₃)₂, ³JHH = 7.0 Hz), 1.62 (d, 1H, Cy-CH, ³JHH = 12.9 Hz),1.70−1.82 (m, 6H, Cy-CH₂), 1.94−2.02 (m, 1H, Cy-CH₂), 3.14 (sept, 2H, CH(CH₃)₂, ³JHH = 6.9 Hz), 3.23 (sept, 2H, CH(CH₃)₂, ³JHH = 6.9 Hz), 5.21 (s, 1H, NH), 7.03 (t, 1H, p-C₆H₃), 7.12−7.17 (m, 4H, m-C₆H₃), 7.26 (m, 1H, p-C₆H₃)
¹³C{¹H} NMR (101 MHz, CDCl₃, 298 K)	δ / ppm = 22.5 (CH(CH₃)₂), 23.0 (CH(CH₃)₂), 24.2 (CH(CH₃)₂), 25.5 (CH(CH₃)₂), 26.0 (Cy-CH₂), 26.2 (Cy-CH₂), 28.2 (CH(CH₃)₂), 28.4 (CH(CH₃)₂), 31.1 (CyCH₂), 39.2 (Cy-CH), 122.8 (p-C₆H₃), 123.1 (m-C₆H₃), 123.7 (m-C₆H₃), 1278.0 (p-C₆H₃), 133.2 (ipso-C₆H₃), 139.1 (o-C₆H₃), 144.4 (o-C₆H₃), 147.2 (ipso-C₆H₃), 159.1 (NCN) ppm
Single-crystal XRD	CCDC No. 2538181; formula C₃₁H₄₆N₂; Mr 446.70; crystal system monoclinic; space group I2/c; a = 17.9572(6) Å; b = 17.1090(6) Å; c = 35.9280(11) Å; α = 90°; β = 103.866(2)°; γ = 90°; V = 10716.5(6) Å³; Z = 16; ρcalc = 1.107 g cm⁻³; μ = 0.472 mm⁻¹; F(000) = 3936; reflections (unique) 123613(10621); S = 1.02; R1(wR2) (F² > 2σ(F²)) = 0.0395(0.0978); Rint = 0.027; min./max diff map = −0.24, 0.25 e Å⁻³

{(Cy)C(=O)N(H)(2,6-Dipp)}
¹H NMR (400 MHz, CDCl₃, 298 K)	δ / ppm = 1.19 (d, 6H, CH(CH₃)₂, ³JHH = 6.8 Hz), 1.28−1.41 (m, 3H, Cy-CH₂), 1.52−1.62 (m, 3H, Cy-CH₂), 1.71−1.75 (m, 1H, Cy-CH₂), 1.84−1.88 (m, 2H, Cy-CH₂), 2.03−2.07 (m, 2H, Cy-CH₂), 2.36 (tt, , 1H, Cy-CH, ³JHH = 11.8, 3.5 Hz), 3.04 (s, 1H, NH), 6.65 (d, 2H, m-C₆H₃, ³JHH = 7.6), 7.16 (t, 1H, p-C₆H₃, ³JHH = 7.7)
¹³C{¹H} NMR (101 MHz, CDCl₃, 298 K)	δ / ppm = 23.69 (CH(CH₃)₂), 25.91 (Cy-CH₂), 25.95 (Cy-CH₂), 28.84 (CH(CH₃)₂), 30.10 (Cy-CH₂), 46.11 (Cy-CH), 123.49 (m-C₆H₃), 128.36 (p-C₆H₃), 131.29 (ipso-C₆H₃), 146.40 (o-C₆H₃), 175.27 (C=O)
Single-crystal XRD	CCDC No. 2538184; formula C₁₉H₂₉NO; Mr 287.43; crystal system monoclininc; space group P2₁/c; a = 18.0938(11) Å; b = 9.0133(6) Å; c = 23.0907(14) Å; α = 90°; β = 111.682(2)°; γ = 90°; V = 3499.3(4) Å³; Z = 8; ρcalc = 1.091 g cm⁻³; μ = 0.504 mm⁻¹; F(000) = 1264; reflections (unique) 29188(6879); S = 1.15; R1(wR2) (F² > 2σ(F²)) = 0.0593(0.1601); Rint = 0.046; min./max diff map = −0.27, 0.27 e Å⁻³

[K(L)(THF)₃]
Single-crystal XRD	CCDC No. 2538183; formula C₄₇H₇₇KN₂O₄; Mr 773.21; crystal system triclinic; space group P-1; a = 11.5699(5) Å; b = 13.3245(5) Å; c = 15.7619(7) Å; α = 82.163(2)°; β = 86.663(2)°; γ = 71.985(2)°; V = 2288.9(2) Å³; Z = 2; ρcalc = 1.122 g cm⁻³; μ = 1.331 mm⁻¹; F(000) = 848; reflections (unique) 43140(8893); S = 1.06; R1(wR2) (F² > 2σ(F²)) = 0.0389(0.1068); Rint = 0.033; min./max diff map = −0.33, 0.36 e Å⁻³

Calcium bis-amidinate complex
Identifier	1-Ca
¹H NMR (500 MHz, C₆D₆, 298 K)	δ / ppm = 0.52 – 0.71 (m, 7H, Cy-CH₂), 1.01 – 1.35 (m, 57H, (CH₃)₂CH and Cy-CH₂), 1.74 (d, 4H, JHH = 12.0Hz, Cy-CH₂), 2.46 (t, 2H, JHH = 12.1 Hz, Cy-CH), 3.45 (br, 8H, Δν₁/₂ = 27 Hz, CH(CH₃)₂), 7.06 (s, 12H, C₆H₃)
¹³C{¹H} NMR (125 MHz, C₆D₆, 298 K)	δ / ppm = 22.30 ((CH₃)₂CH), 25.38 ((CH₃)₂CH), 26.07 (Cy-CH₂), 26.61 (Cy-CH₂), 28.70 (CH(CH₃)₂), 29.97 (Cy-CH₂), 44.51 (Cy-CH), 123.06 (p-C₆H₃), 123.62 (m-C₆H₃), 141.86 (o-C₆H₃), 144.82 (ipso-C₆H₃), 176.79 (NCN)
Elemental analysis	Calc. for C₆₂H₉₀N₄Ca: C, 79.9; H, 9.7; N, 6.0. Found: C, 78.7; H, 9.4; N, 5.85 %
FTIR	υ / cm⁻¹ = 3059 (w), 2956 (m), 2923 (m), 2852 (w), 1444 (s), 1381 (w), 1355 (s), 1314 (s), 1303 (s), 1245 (s), 1206 (m), 1175 (w), 1157 (w), 1135 (w), 1102 (w), 1056 (w), 1044 (w), 1020 (w), 957 (m), 931 (w), 906 (w), 873 (w), 832 (w), 801 (m), 778 (s), 764 (s), 745 (s), 691 (w), 587 (w), 514 (w), 421 (m)
Single-crystal XRD, C₆₇H₁₀₂CaN₄	CCDC No. 2538179; Mr 1003.60; crystal system monoclinic; space group P2₁/c; a = 12.2049(6) Å; b = 25.7335(13) Å; c = 20.3969(11) Å; α = 90°; β = 96.294(2)°; γ = 90°; V = 6367.5(6) Å³; Z = 4; ρcalc = 1.047 g cm⁻³; μ = 1.136 mm⁻¹; F(000) = 2208; reflections (unique) 89337(12493); S = 1.02; R1(wR2) (F² > 2σ(F²)) = 0.0374(0.0990); Rint = 0.024; min./max diff map = −0.21, 0.26 e Å⁻³
Single-crystal XRD, C₆₂H₉₀CaN₄	CCDC No. 2538177; Mr 931.46; crystal system monoclinic; space group P2₁/c; a = 18.7110(2) Å; b = 14.1933(2) Å; c = 21.6267(2) Å; α = 90°; β = 92.290(2)°; γ = 90°; V = 5738.89(9) Å³; Z = 4; ρcalc = 1.078 g cm⁻³; μ = 0.149 mm⁻¹; F(000) = 2040; reflections (unique) 305034(30564); S = 1.02; R1(wR2) (F² > 2σ(F²)) = 0.0462(0.1247); Rint = 0.041; min./max diff map = −0.50, 0.61 e Å⁻³

Strontium bis-amidinate complex
Identifier	1-Sr
¹H NMR (500 MHz, C₆D₆, 298 K)	δ / ppm = 0.69 – 0.75 (m, 6H, Cy-CH₂), 1.06 (d, 24H, ³JHH = 6.8 Hz, (CH₃)₂CH), 1.19 – 1.41 (m, 38H, (CH₃)₂CH and Cy-CH₂ and THF-CH₂), 1.72 (d, 4H, JHH = 12.2 Hz, Cy-CH₂), 2.54 (t, 2H, JHH = 12.0 Hz, Cy-CH), 3.48 (t, 4H, ³JHH = 6.6 Hz, THF-CH₂), 3.54 (sept, 8H, ³JHH = 6.8 Hz, CH(CH₃)₂), 7.05 – 7.08 (m, 4H, p-C₆H₃), 7.11 – 7.13 (m, 8H, m-C₆H₃)
¹³C{¹H} NMR (125 MHz, C₆D₆, 298 K)	δ / ppm = 23.10 ((CH₃)₂CH), 25.39 (THF-CH₂), 25.80 ((CH₃)₂CH), 26.32 (Cy-CH₂), 26.97 (Cy-CH₂), 28.46 (CH(CH₃)₂), 30.59 (Cy-CH₂), 45.30 (Cy-CH), 68.66 (THF-CH₂), 122.67 (p-C₆H₃), 123.28 (m-C₆H₃), 141.69 (o-C₆H₃), 147.16 (ipso-C₆H₃),, 175.53 (NCN)
Elemental analysis	Calc. for C₆₆H₉₈N₄OSr: C, 75.4; H, 9.4; N, 5.3. Found: C, 74.8; H, 9.4; N, 5.3 %
FTIR	υ / cm⁻¹ = 3056 (w), 2961 (m), 2926 (m), 2862 (w), 1453 (s), 1437 (s), 1381 (m), 1355 (s), 1309 (s), 1242 (s), 1199 (m), 1175 (m), 1134 (w), 1099 (m), 1031 (m), 947 (m), 934 (w), 905 (w), 875 (m), 832 (w), 801 (m), 777 (s), 764 (s), 746 (s), 689 (w), 587 (w), 508 (w), 421 (s)
Single-crystal XRD	CCDC No. 2538176; formula C₆₆H₉₈N₄OSr; Mr 1051.10; crystal system triclinic; space group P-1; a = 12.4496(5) Å; b = 14.3864(6) Å; c = 18.7545(8) Å; α = 97.399(2)°; β = 93.147(2)°; γ = 112.763(2)°; V = 3051.4(2) Å³; Z = 2; ρcalc = 1.144 g cm⁻³; μ = 1.540 mm⁻¹; F(000) = 1136; reflections (unique) 75680(11575); S = 1.05; R1(wR2) (F² > 2σ(F²)) = 0.0273(0.11575); Rint = 0.021; min./max diff map = −0.33, 0.62 e Å⁻³

[Ba(anti-L)₂]
Identifier	1-Ba
¹H NMR (500 MHz, C₆D₆, 298 K)	δ / ppm =1.00 (s, br, 31H, Δν₁/₂ = 70 Hz, CH(CH₃)₂ and Cy-CH₂), 1.28 (d, 24H, ³JHH = 6.8 Hz, CH(CH₃)₂), 1.53 (s, br, 7H, Δν₁/₂ = 84 Hz, Cy-CH₂), 1.82 (s, br, 5H, Δν₁/₂ = 35 Hz, Cy-CH₂), 2.11 (s, br, 3H, Δν₁/₂ = 43 Hz, Cy-CH₂ and Cy-CH), 3.36 (s, br, 8H, Δν₁/₂ = 43 Hz, CH(CH₃)₂), 6.99 (s, 4H, p-C₆H₃), 7.07 (s, 8H, m-C₆H₃)
¹H VT-NMR (500 MHz, C₇D₈, 238–298 K)	The proton signal at 3.36 ppm detected at ambient temperature splits into three peaks at 238 K with a relative integration ratio of 1:1:2
¹H NMR, methine-signal assignment (C₆D₆, 298 K)	The distinctive septet of the methine proton of the isopropyl groups was broadened (Δν₁/₂ = 43 Hz), implying high conformational flexibility in solution
¹³C{¹H} NMR (125 MHz, C₆D₆, 248 K)	δ / ppm = 21.84, 22.88, 23.13, 23.73, 26.01, 26.43, 26.62, 26.97, 27.46, 28.24, 28.41, 30.33, 32.12, 32.41, 40.84, 44.88, 120.78, 122.52, 122.89, 123.56, 123.92, 141.12, 142.91, 144.91 145.26, 146.23, 146.88, 161.66, 171.04, 172.83
¹³C{¹H} VT-NMR (126 MHz, C₇D₈, 248 K)	Three sets of aryl carbon signals and two sets of quaternary carbons corresponding to the central atom of the NCN backbone, indicating the presence of both syn-coordination (κ²) and anti-coordination (κ¹) of the amidinate ligands in solution
Elemental analysis	Calc. for C₆₂H₉₀N₄Ba: C, 72.4; H, 8.8; N, 5.45. Found: C, 72.4; H, 8.85; N, 5.3 %
FTIR	υ / cm⁻¹ = 2960 (m), 2933 (s), 2858 (w), 1528 (s), 1461 (m), 1448 (m), 1427 (s), 1380 (s), 1356 (m), 1325 (s), 1306 (m), 1284 (s), 1255 (m), 1237 (s), 1177 (s), 1159 (w), 1135 (w), 1096 (m), 1046 (w), 946 (m), 889 (w), 871 (m), 840 (m), 805 (s), 790 (m), 773 (s), 705 (w), 675 (w), 612 (w), 543 (w), 445 (m), 431 (m)
Single-crystal XRD, crystallographic data	SI: CCDC No. 2538175; formula C₇₁H₁₁₁BaN₄; Mr 1157.97; crystal system monoclinic; space group C2/c; a = 24.9468(11) Å; b = 13.7969(6) Å; c = 9.8946(5) Å; α = 90°; β = 107.952(2)°; γ = 90°; V = 3239.8(3) Å³; Z = 2; ρcalc = 1.187 g cm⁻³; μ = 5.071 mm⁻¹; F(000) = 1242; reflections (unique) 20621(3283); S = 1.10; R1(wR2) (F² > 2σ(F²)) = 0.0375(0.1040); Rint = 0.043; min./max diff map = −0.97, 1.49 e Å⁻³
Single-crystal XRD, structural description	Main: space group C2/m; pseudo-C₂h symmetry; Z′ = 0.25; N–Ba–N = 180°; Ba–N = 2.935(3) Å

{K₂[Ba(L)₂]∙2e⁻}
Identifier	2
Total-reflectance UV–vis (solid-state powder, room temperature)	Broad band in the region 400-450 nm
SQUID magnetometry	Magnetic susceptibility measured as a function of temperature (2–300 K) and isothermal magnetization measured as a function of magnetic field (0–50 kOe) at 2 K; largely diamagnetic response; negative magnetization ca. –3.7*10⁻³ Nβ at 50 kOe, measured at 2 K
CW X-band EPR (∼9.4 GHz)	An EPR signal was observed at all temperatures between 40 and 270 K; its intensity noticeably increases with decreasing temperature while its overall appearance remains largely unchanged; ca. 0.003 % is paramagnetically active; gx,y,z = 2.006, 2.002, 1.975; gav = 1.994; characteristic of anionic electrons trapped in the cavities of solid state electrides
X-band EDFS	Measured between 3 and 70 K; rhombic g and overall gav = 1.994
Spin-lattice relaxation time, T1 (X-band, 3 K)	OP1 (x,y): T1 = 11798(73) μs, TSD = 970(11) μs; OP2 (z): T1 = 11621(112) μs, TSD = 1465(26) μs
Phase memory time, Tm (X-band)	3 K, OP1 (x,y): Tm = 1185(2) ns, x = 1.0 and 830(1) ns, x = 0.68; 3 K, OP2 (z): Tm = 1185(2) ns, x = 1.0 and 830(1) ns, x = 0.7; 70 K, OP1 (x,y): Tm = 584(2) ns, x = 1.08; 70 K, OP2 (z): Tm = 588(2) ns, x = 1.12
Spin-relaxation fit reporting	TSD is the spectral-diffusion time constant in the inversion-recovery model; x is the stretch factor in the echo-decay model; the echo-decay curves at 3 K required a bi-exponential fit
ESEEM (3 K)	Frequency-domain spectra reveal nuclear resonance peaks corresponding to ¹H, ¹³⁵,¹³⁷Ba and ¹⁴N
HYSCORE (X-band, 9.71 GHz, 10 K)	Analysis of the spectra provided clear evidence of magnetic coupling between the anionic electron and the ¹H, ¹³⁵,¹³⁷Ba and ¹⁴N nuclei from its environment

[{Ba₂(anti-L)₂(μ₂-H)}₂(μ₄-C₁₂H₁₀)]·6C₆H₆
Identifier	3
Evans method (¹H NMR, 400 MHz, C₆D₆, 298 K)	μeff = 2.21 μB
Elemental analysis	Calc. for C₁₃₆H₁₉₂N₈Ba₄·6C₆H₆: C, 69.86; H, 7.77; N, 3.79. Found: C, 63.54; H, 7.31; N, 3.62 %. Low carbon values were obtained consistently
UV–vis (0.1 M, hexane)	λmax/nm (ε/dm³ mol⁻¹ cm⁻¹): 542 (7970)
FTIR	υ / cm⁻¹ = 2959 (m), 2928 (m), 2863 (w), 2852 (w), 1631 (s), 1586 (w), 1559 (w), 1516 (s), 1460 (m), 1448 (m), 1425 (s), 1386 (m), 1359 (w), 1334 (m), 1324 (m), 1310 (w), 1285 (w), 1258 (s), 1238 (m), 1172 (w), 1096 (m), 1015 (s), 949 (m), 935 (w), 892 (w), 869 (w), 840 (w), 799 (s), 781 (s), 756 (s), 737 (m), 698 (m), 669 (w), 603 (m), 589 (m), 511 (m), 445 (w), 424 (w)
Single-crystal XRD	CCDC No. 2538182; formula C₁₇₂H₂₃₀Ba₄N₈; Mr 2987.99; crystal system monoclinic; space group C2/c; a = 34.6884(8) Å; b = 15.0161(4) Å; c = 30.3168(8) Å; α = 90°; β = 94.607(1)°; γ = 90°; V = 15740.5(7) Å³; Z = 4; ρcalc = 1.249 g cm⁻³; μ = 8.056 mm⁻¹; F(000) = 6168; reflections (unique) 96149(15499); S = 1.04; R1(wR2) (F² > 2σ(F²)) = 0.0463(0.1103); Rint = 0.143; min./max diff map = −0.85, 1.22 e Å⁻³; Ba–N = 2.680(3) and 2.692(3) Å; hydrides clearly identified in the residual electron density map; Ba–H = 2.46(3) and 2.57(3) Å; C(63)–C(63)ⁱ = 1.384(8) Å, revealing some double bond character and a quinoid-type structure of the biphenyl dianion; phenyl-group dihedral angle = 17.4(2)°
CW X-band EPR (9.4 GHz, polycrystalline, 270 K)	Isotropic paramagnetic signal with 1.6 mT linewidth, Lorentzian shape, at g = 2.0023; ca. 0.05 % is paramagnetic; upon cooling, the signal increases in intensity and becomes more rhombic; assigned to uncompensated antiferromagnetic coupling within the biphenyl entity
ESEEM	Strong ESEEM from ¹H, ¹³C, ¹³⁵Ba and ¹³⁷Ba nuclei
Spin-lattice relaxation time, T1 (X-band)	3 K: OP1 7287(36) μs, TSD 1232(12) μs; OP2 5581(6) μs, TSD 446(5) μs; OP3 7280(40) μs, TSD 1178(10) μs. 5 K: OP1 5405(31) μs, TSD 1034(12) μs; OP2 3228(12) μs, TSD 319(4) μs; OP3 4233(21) μs, TSD 661(11) μs. 10 K: OP1 1591(13) μs, TSD 217(4) μs; OP2 746(13) μs, TSD 108(3) μs; OP3 2003(26) μs, TSD 312(8) μs. 20 K: OP1 154(1) μs, TSD 33(1) μs; OP2 154(3) μs, TSD 33(1) μs; OP3 280(15) μs, TSD 47(3) μs
Phase memory time, Tm (X-band)	5 K: OP1 2113(3) ns, x = 1.6; OP2 2382(3) ns, x = 1.6; OP3 2364(4) ns, TSD = 1.6. 10 K: OP1 1752(1) ns, x = 1.6; OP3 1953(3) ns, TSD = 1.6. 20 K: OP1 1472(3) ns, x = 1.6; OP2 1314(1) ns, x = 1.6; OP3 1705(4) ns, TSD = 1.6
Spin-relaxation fit reporting	TSD is the spectral-diffusion time constant in the inversion-recovery model; x is the stretch factor in the echo-decay model
HYSCORE (X-band, 9.7 GHz)	Cross-peaks at the Larmor frequencies of ¹H, ¹³C, ¹³⁵Ba and ¹³⁷Ba nuclei

[{Ba₂(anti-L)₂(μ₂-H)}₂(μ₄-C₁₄H₁₄)]
Identifier	4
¹H NMR (400 MHz, C₇D₈, 298 K)	δ / ppm = –0.01 (br, Δν₁/₂ = 60 Hz), 0.23 (br, Δν₁/₂ = 38 Hz), 1.08 (br, Δν₁/₂ = 47 Hz), 1.19 (br, Δν₁/₂ = 129 Hz), 1.26 (d, ³JHH = 6.8 Hz), 1.35 (br, Δν₁/₂ = 98 Hz), 1.48 (br, Δν₁/₂ = 24 Hz), 1.67 (br, Δν₁/₂ = 18 Hz), 1.70 (s), 1.86 (br, Δν₁/₂ = 62 Hz), 2.21 (br, Δν₁/₂ = 42 Hz), 3.52 (br, Δν₁/₂ = 123 Hz), 3.70 (br, Δν₁/₂ = 90 Hz), 3.98 (br, Δν₁/₂ = 14 Hz), 4.26 (br, Δν₁/₂ = 49 Hz), 7.45 (br, Δν₁/₂ = 76 Hz), 7.57 (br, Δν₁/₂ = 38 Hz), 8.43 (br, Δν₁/₂ = 33 Hz), 8.48 (s)
Evans method (¹H NMR, 400 MHz, C₆D₆, 298 K)	μeff = 3.05 μB
UV–vis (0.1 M, hexane)	λmax/nm (ε/dm³ mol⁻¹ cm⁻¹): 541 (9200)
FTIR	υ / cm⁻¹ = 2957 (m) ,2926 (m), 2850 (w), 1558 (w), 1513 (s), 1460 (w), 1449 (w), 1425 (s), 1385 (w), 1357 (w), 1336 (m), 1307 (w), 1285 (m), 1250 (w), 1235 (m), 1169 (m), 1101 (w), 1037 (w), 947 (m), 889 (w), 869 (w), 840 (m),799 (m),780 (m), 766 (m),753 (s), 675 (s), 601 (m), 588 (m), 512 (m)
Single-crystal XRD	CCDC No. 2538180; formula C₁₆₆H₂₂₇Ba₄N₈; Mr 2883.90; crystal system monoclinic; space group P2₁/c; a = 22.3650(8) Å; b = 14.2924(6) Å; c = 24.7228(9) Å; α = 90°; β = 14.2924(6)°; γ = 90°; V = 7866.4(5) Å³; Z = 2; ρcalc = 1.218 g cm⁻³; μ = 8.046 mm⁻¹; F(000) = 3006; reflections (unique) 90383(24731); S = 1.09; R1(wR2) (F² > 2σ(F²)) = 0.0827(0.2238); Rint = 0.069; min./max diff map = −1.14, 1.81 e Å⁻³; Ba–N = 2.65(2)–2.768(13) Å; hydrides clearly identified in the residual electron density map; Ba–H = 2.50(3)–2.52(2) Å; C(1)–C(7) = 1.39(3) Å, revealing some double bond character and a quinoid-type structure of the biphenyl dianion; phenyl-group dihedral angle = 23.8(5)°. The relative occupancies of the methyl substituents were estimated using single-crystal XRD, suggesting that the meta-meta coupling product is the most abundant

[{Ba₂(anti-L)₂(μ₂-H)}₂(μ₄-C₁₂H₁₀)]·6C₆H₆ and [{Ba₂(anti-L)₂(μ₂-H)}₂(μ₄-C₁₄H₁₄)]
¹H NMR	NMR spectroscopic characterization demonstrated their paramagnetic nature, showing significant line broadening in the ¹H NMR spectra of both complexes

[Ba(anti-L)(syn-L)]
Identifier	5
¹H NMR (room temperature)	Same spectrum as originally recorded for 1-Ba
¹H NMR peak annotations (400 MHz, C₆D₆, 298 K)	δ 7.16 (C₆D₆), 7.06, 7.01, 7.00, 6.98, 3.37, 2.12, 1.83, 1.53, 1.29, 1.27, 1.01, 0.12
Single-crystal XRD	CCDC No. 2538178; formula C₆₂H₉₀BaN₄; Mr 1028.71; crystal system monoclinic; space group P2₁/c; a = 11.2975(6) Å; b = 25.2492(13) Å; c = 19.8701(10) Å; α = 90°; β = 91.343(2)°; γ = 90°; V = 5666.4(5) Å³; Z = 4; ρcalc = 1.206 g cm⁻³; μ = 5.741 mm⁻¹; F(000) = 2184; reflections (unique) 100595(10907); S = 1.08; R1(wR2) (F² > 2σ(F²)) = 0.0515(0.1478); Rint = 0.052; min./max diff map = −1.46, 3.24 e Å⁻³