Synthesis of [K(crypt-222)][(Cp*2Ln)2(μ-Bbim˙)], 2-Ln = Gd, Tb, Dy

To a THF (8–10 mL) solution of the metal complexes, 1-Ln, 2.2.2-cryptand (1 equiv., 1 mL THF) was added and stirred for 5 min. Addition of solid KC₈ (1 equiv.) resulted in an immediate colour change to dark green and the formation of an insoluble gray material, presumably graphite. After stirring for 20 min, the mixture was filtered to remove the insoluble solids and the clear, dark green filtrate was stored at −30 °C for crystallization. Dark green block-shaped crystals of 2-Ln were grown over the course of 3–5 days.

Used masses: 1-Gd: 0.0979 g (0.0900 mmol), 2.2.2-cryptand: 0.0338 mg (0.0898 mmol), KC₈: 0.0122 g (0.0902 mmol). Crystalline yield of 2-Gd: 0.0445 g (0.0296 mmol, 33%). Anal. calcd for C₇₂H₁₀₄N₆O₆KGd₂: C, 57.53; H, 6.97; N, 5.59. Found: C, 57.69; H, 7.42; N, 5.33. IR (ATR, cm⁻¹): 3043 (vw), 2968 (w), 2892 (m), 2850 (m), 2814 (w), 2725 (w), 1552 (m), 1474 (m), 1441 (s), 1355 (m), 1295 (w), 1254 (s), 1217 (s), 1133 (s), 1101 (s), 1077 (s), 1025 (m), 1006 (m), 949 (m), 932 (m), 917 (m), 902 (m), 829 (w), 820 (w), 764 (w), 751 (w), 718 (s).

Used masses: 1-Tb: 0.0722 g (0.0662 mmol), 2.2.2-cryptand: 0.0229 mg (0.0608 mmol), KC₈: 0.0083 g (0.061 mmol). Crystalline yield of 2-Tb: 0.0349 g. (0.0232 mmol, 35%). Anal. calcd for C₇₂H₁₀₄N₆O₆KTb₂: C, 57.40; H, 6.96; N, 5.58. Found: C, 57.23; H, 7.19; N, 5.53. IR (ATR, cm⁻¹): 3043 (w), 2961 (m), 2881 (s), 2851 (s), 2725 (w), 1552 (s), 1474 (w), 1441 (s), 1353 (s), 1293 (w), 1256 (vs), 1218 (s), 1172 (w), 1133 (s), 1100 (vs), 1077 (s), 1006 (s), 948 (vs), 930 (s), 902 (vs), 859 (w), 829 (w), 820 (w), 764 (vw), 751 (w), 718 (s).

Used masses: 1-Dy: 0.0469 g (0.0427 mmol), 2.2.2-cryptand: 0.0175 mg (0.0465 mmol), KC₈: 0.0065 g (0.048 mmol). Crystalline yield of 2-Dy: 0.0183 g (0.0121 mmol, 28%). Anal. calcd for C₇₂H₁₀₄N₆O₆KDy₂: C, 57.13; H, 6.93; N, 5.55. Found: C, 56.97; H, 6.88; N, 5.21. IR (ATR, cm⁻¹): 3042 (vw), 2963 (w), 2881 (s), 2850 (s), 2812 (w), 2721 (w), 1554 (m), 1476 (w), 1441 (s), 1355 (s), 1293 (w), 1257 (vs), 1220 (s), 1174 (w), 1133 (s), 1101 (s), 1077 (s), 1008 (m), 951 (s), 932 (m), 917 (m), 902 (m), 859 (w), 829 (w), 820 (w), 779 (vw), 764 (w), 749 (m), 719 (s), 669 (w).