Table 2. Comparison of the structural characteristics (Å, °) of {LnCu5}3+ 15-metallacrown-5 complexes with octacoordinate Ln III ions and various bidentate anions.
| Complex a | Cu—O/Neq | Ln—Oeq | Ln—Oaq | Ln⋯Cu | Cu⋯Cu | Deviation of Ln III from Cu5 plane | LnO8 geometry b |
|---|---|---|---|---|---|---|---|
| Pr—SO4 | 1.898 (2)–2.013 (2) | 2.4247 (18)–2.4716 (18) | 2.495 (2)–2.528 (2) | 3.862 (3)–3.923 (2) | 4.530 (2)–4.604 (2) | 0.459 | SAPR-8 |
| Nd—SO4 | 1.898 (2)–2.0156 (19) | 2.4145 (16)–2.4642 (16) | 2.4787 (18)–2.5108 (17) | 3.862 (3)–3.915 (4) | 4.524 (4)–4.598 (5) | 0.452 | SAPR-8 |
| Sm—SO4 | 1.900 (4)–2.015 (4) | 2.398 (3) −2.450 (3) | 2.441 (4)–2.484 (4) | 3.8539 (9)–3.9083 (8) | 4.518 (1)–4.592 (1) | 0.439 | SAPR-8 |
| Eu—SO4 | 1.896 (3)–2.013 (3) | 2.389 (3)–2.437 (3) | 2.431 (3)–2.467 (3) | 3.844 (7)–3.899 (8) | 4.504 (8)–4.585 (9) | 0.439 | SAPR-8 |
| Eu—CO3 | 1.886 (14)–2.022 (13) | 2.406 (11)–2.493 (11) | 2.369 (13)–2.392 (15) | 3.890 (2)–3.911 (3) | 4.575 (3)–4.589 (3) | 0.351 | TDD-8 |
| Eu-OAc | 1.902 (3)–2.041 (2) | 2.440 (4)–2.515 (2) | 2.4057 (18)–2.443 (2) | 3.8517 (4)–3.9049 (4) | 4.5664 (5)–4.6074 (4) | 0.469 | TDD-8 |
| Gd—SO4 | 1.892 (3)–2.014 (3) | 2.378 (3)–2.434 (3) | 2.398 (3)–2.452 (3) | 3.838 (7)–3.897 (9) | 4.501 (8)–4.578 (11) | 0.430 | SAPR-8 |
| Gd—CO3 | 1.898 (2)–2.022 (2) | 2.381 (2)–2.484 (2) | 2.288 (17)–2.396 (10) | 3.8699 (5)–3.9097 (5) | 4.5677 (7)–4.5846 (7) | 0.337 | TDD-8 |
| Gd-OAc | 1.890 (12)–2.041 (11) | 2.393 (3)–2.438 (9) | 2.426 (10)–2.512 (10) | 3.845 (2)–3.897 (2) | 4.562 (2)–4.602 (2) | 0.458 | TDD-8 |
| Tb—SO4 | 1.890 (4)–2.018 (4) | 2.370 (3)–2.430 (3) | 2.383 (3)–2.451 (3) | 3.8398 (8)–3.8944 (8) | 4.501 (1)–4.577 (1) | 0.427 | SAPR-8 |
| Tb-OAc | 1.889 (11)–2.036 (11) | 2.383 (9)–2.431 (9) | 2.409 (10)–2.488 (10) | 3.840 (2)–3.896 (2) | 4.562 (2)–4.598 (2) | 0.445 | TDD-8 |
| Dy—SO4 | 1.8908 (18)–2.0206 (19) | 2.3640 (15) −2.4234 (15) | 2.3665 (17)–2.4334 (17) | 3.834 (2)–3.889 (2) | 4.493 (2)–4.573 (2) | 0.424 | SAPR-8 |
| Dy—CO3 | 1.898 (3)–2.022 (3) | 2.382 (3)–2.469 (3) | 2.27 (2)–2.380 (8) | 3.8715 (5)–3.9016 (6) | 4.5645 (7)–4.5797 (8) | 0.354 | TDD-8 |
| Ho—SO4 | 1.887 (3)–2.016 (3) | 2.356 (2)–2.416 (2) | 2.357 (2)–2.417 (2) | 3.827 (2)–3.884 (2) | 4.485 (2)–4.565 (2) | 0.422 | SAPR-8 |
| Ho—CO3 | 1.898 (2)–2.022 (2) | 2.374 (2)–2.475 (2) | 2.30 (3)–2.374 (12) | 3.8670 (5)–3.9021 (5) | 4.5583 (7)–4.5808 (7) | 0.330 | TDD-8 |
Notes: (a) Complex Tb—SO4 is 1; Ln-SO4 correspond to the [LnCu5(GlyHA)5(SO4)(H2O)6.5]2(SO4) series with Ln = Pr, Nd, Sm, Eu, Gd, Dy and Ho described in (Pavlishchuk et al., 2011 ▸); Ln-CO3 are [LnCu5(GlyHA)5(CO3)(NO3)(H2O)5] with Ln = Eu, Gd, Dy and Ho described in Pavlishchuk et al. (2019 ▸) and Stemmler et al. (1999 ▸); Ln-OAc are [LnCu5(GlyHA)5(OAc)(H2O)5](NO3)2 Ln = Eu, Gd and Tb described in Katkova et al. (2015a ▸) and Meng et al. (2016 ▸). (b) LnO8 geometries: SAPR-8 = square antiprism (D4d) and TDD-8 = triangular dodecahedron (D 2d ).