2.2.1. General Synthetic Procedure for Complexes [M(flrx)2(O-Donor)x] (x = 0 or 2) (Complexes 1–5)
For the synthesis of complexes 1–5, a methanolic solution containing fleroxacin (0.5 mmol, 185 mg) and KOH (0.5 mmol, 0.5 mL 1 M) was stirred for 60 min. Afterwards, the solution was added into a methanolic solution of the corresponding salt MCl2 (0.25 mmol) at RT. The reaction mixture was stirred for 1 h and left to slowly evaporate. After a few days, (micro)crystalline products were collected.
[Cu(flrx)2], 1: For the synthesis of complex 1, CuCl2·2H2O (43 mg, 0.25 mmol) was used as MCl2. Light-blue product of 1 (110 mg, 55%) was collected after three days. Anal. calc. for [Cu(flrx)2] (C34H34CuF6N6O6) (MW = 800.22). C: 51.03, H: 4.29, N: 10.51%; found: C: 51.30, H: 4.15, N: 10.39%. ESI–MS(+), m/z: found, 799.0; calc. for MW, 800.2.IR (KBr disk), νmax (cm−1): ν(C=O)pyr, 1619 (s); νasym(COO), 1589 (s); νsym(COO), 1371 (s); Δν(COO) = νasym(COO) –νsym(COO) = 218. UV–vis: as nujol mull, λ (in nm): 665, 395; in DMSO, λ (in nm) (ε, in M–1 cm–1): 680 (55), 392 (shoulder (sh)) (340), 335 (5900), 320 (3500), 293 (10,500). μeff at RT = 1.86 BM. The complex is soluble in DMSO (ΛM = 3 mho·cm2·mol−1, in 1 mM DMSO solution) and partially soluble in methanol and DMF.
[Mn(flrx)2(H2O)2], 2: For the synthesis of complex 2, ΜnCl2·4H2O (49 mg, 0.25 mmol) was used as the MCl2. Yellow product of 2 (115 mg, 55%) was collected after a month. Anal. calc. for [Mn(flrx)2(H2O)2] (C34H48F6MnN6O8) (MW = 827.64). C: 49.34, H: 4.63, N: 10.15%; found: C: 49.30, H: 4.85, N: 10.29%. ESI–MS(+), m/z: found, 878.19; calc. for MW + 1 + H2O + MeOH, 878.70. IR (KBr disk), νmax (cm−1): ν(C=O)pyr, 1619 (s); νasym(COO), 1573 (s); νsym(COO), 1372 (s); Δv(COO) = 201. UV–vis: as nujol mull, λ (in nm): 405 (sh); in DMSO, λ (in nm) (ε, in M–1 cm–1): 385(sh) (190), 333 (4500), 288 (8500). μeff at RT = 6.05 BM. The complex is soluble in methanol, DMF and DMSO (ΛM = 3 mho·cm2·mol−1, in 1 mM DMSO solution).
[Zn(flrx)2(MeOH)2]·2MeOH, 3·2MeOH: For the synthesis of complex 3, ZnCl2 (34 mg, 0.25 mmol) was used as the MCl2. Off-white crystals of 3 (120 mg, 55%) suitable for X-ray crystallography were collected after three weeks. Anal. calc. for [Zn(flrx)2(MeOH)2] (C36H42F6N6O8Zn) (MW = 866.14). C: 49.92, H: 4.89, N: 9.70%; found: C: 50.15, H: 4.95, N: 9.47%. ESI–MS(+), m/z: found, 899.12; calc. for MW+1+MeOH, 899.14. IR (KBr disk), νmax (cm–1): ν(C=O)pyr, 1618 (s); νasym(COO), 1580 (s); νsym(COO), 1373 (s); Δν(COO) = 207. UV–vis: as nujol mull, λ (in nm): 401 (sh); in DMSO, λ (in nm) (ε, in M–1 cm–1): 387(sh) (250), 333 (4900), 290 (10,000). 1H NMR spectrum in DMSO-d6, δ (in ppm): 8.85 (2H, H2–flrx), 7.79 (2H, H5–flrx), 4.88–4.78 (8H, H1b– and H1a–flrx), 4.59 (6H, H–MeOH), 3.40 (8H, H2′,6′–flrx), 2.44 (8H, H3′,5′–flrx), 2.19 (6H, H4′a–flrx). The complex is soluble in DMSO (ΛM = 7 mho·cm2·mol−1, in 1 mM DMSO solution) and partially soluble in DMF and methanol.
[Co(flrx)2(MeOH)2], 4: For the synthesis of complex 4, CoCl2·6H2O (59 mg, 0.25 mmol) was used as the MCl2. Orange microcrystalline product of 4 (125 mg, 60%) was collected after a month. Anal. calc. for [Co(flrx)2(MeOH)2] (C36H42CoF3N6O8) (MW = 859.69). C: 50.30, H: 4.92, N: 9.78%; found: C: 50.45, H: 4.75, N: 9.54%. ESI–MS(+), m/z: found, 886.24. IR (KBr disk), νmax (cm–1): ν(C=O)pyr, 1615 (s); νasym(COO), 1578 (s); νsym(COO), 1372 (s); Δν(COO) = 206. UV–vis: as nujol mull, λ (in nm): 634, 525, 425 (sh); in DMSO, λ (in nm) (ε, in M−1 cm−1): 630 (sh) (15), 540 (25), 435 (sh) (45), 385(sh) (170), 331, (3200), 288 (6200). μeff at RT = 4.15 BM. The complex is soluble in methanol, DMF and DMSO (ΛM = 5 mho·cm2·mol–1, in 1 mM DMSO solution) and partially soluble in CH3CN and CH2Cl2.
[Ni(flrx)2(MeOH)2], 5: For the synthesis of complex 5, NiCl2·6H2O (59 mg, 0.25 mmol) was used as the MCl2. Green product of 5 (120 mg, 55%) was collected after two months. Anal. calc. for [Ni(flrx)2(MeOH)2] (C36H42F6N6NiO8) (MW = 859.47). C: 50.31, H: 4.93, N: 9.78%; found: C: 50.18, H: 4.78, N: 9.69%. ESI–MS(+), m/z: found, 889.81; calc. for MW + MeOH, 891.47.IR (KBr disk), νmax (cm–1): ν(C=O)pyr, 1619 (s); νasym(COO), 1578 (s); νsym(COO), 1372 (s); Δv(COO) = 207. UV–vis: as nujol mull, λ (in nm): 975, 630, 401(sh); in DMSO, λ (in nm) (ε, in M−1 cm−1): 995 (10), 615 (20), 395 (sh) (60), 335 (2700), 289 (7100); 10Dq = 10050 cm−1, B = 761 cm−1, 10Dq/B = 13.2. μeff at RT = 2.90 BM. The complex is soluble in DMF and DMSO (ΛM = 5 mho·cm2·mol−1, in 1 mM DMSO solution) and partially soluble in methanol.
2.2.2. General Synthetic Procedure for Complexes [Cu(flrx)(N,N′-Donor)Cl] (N,N′-Donor = bipy, bipyam, phen), (Complexes 6–8)
The complexes of the formula [Cu(flrx)(N,N′-donor)Cl] were prepared by the addition of a methanolic solution of fleroxacin (0.25 mmol, 92 mg), which was deprotonated by KOH (0.25 mmol, 0.25 mL 1 M) after 1 h stirring into a methanolic solution (5 mL) of CuCl2·2H2O (43 mg,0.25 mmol) at RT, simultaneously with a methanolic solution (5 mL) of the corresponding N,N′-donor (0.25 mmol). The reaction mixture was stirred for additional 15 min. After a few days, the (micro)crystalline product was formed and collected with filtration.
[Cu(flrx)(bipy)Cl], 6: For the synthesis of complex 6, bipy (39 mg, 0.25 mmol) was used as the N,N′-donor. Blue crystals of 6 (75 mg, 50%) suitable for X-ray crystallography were collected after two weeks. Anal. calc. for [Cu(flrx)(bipy)Cl] (C27H25ClCuF3N5O3) (MW = 614.91). C: 52.74, H: 4.10, N: 11.39%; found: C: 52.50, H: 3.99, N: 11.30%. IR (KBr disk), νmax (cm−1): ν(C=O)pyr, 1620 (s); νasym(COO), 1589 (s); νsym(COO), 1363 (s); Δν(COO) = 226; ρ(C–H)bipy, 778 (m). UV–vis: as nujol mull, λ (in nm): 665, 402 (sh); in DMSO, λ (in nm) (ε, in M−1 cm−1): 645 (95), 389 (sh) (220), 333 (2800), 315 (3500), 294 (7900). μeff at RT = 1.80 BM. The complex is soluble in methanol, DMF and DMSO (ΛM = 5 mho·cm2·mol−1, in 1 mM DMSO solution) and partially soluble in CH3CN and CH2Cl2.
[Cu(flrx)(bipyam)Cl], 7: For the synthesis of complex 7, bipyam (43 mg, 0.25 mmol) was used as the N,N′-donor. Blue–green crystals of 7 (85 mg, 55%) suitable for X-ray crystallography were collected after a month. Anal. calc. for [Cu(flrx)(bipyam)Cl] (C27H26ClCuF3N6O3) (MW = 638.54). C: 50.79, H: 4.10, N: 13.16%; found: C: 51.05, H: 4.02, N: 12.94%. IR (KBr disk), νmax (cm−1): ν(C=O)pyr, 1621 (s); νasym(COO), 1585 (s); νsym(COO), 1373 (s); Δν(COO) = 212; ρ(C–H)bipyam, 781 (m). UV–vis: as nujol mull, λ (in nm): 655, 405; in DMSO, λ (in nm) (ε, in M−1 cm−1): 660 (80), 390(sh) (200), 345 (sh) (2100), 319 (5100), 295 (7500). μeff at RT = 1.78 BM. The complex is soluble in MeOH, CH3CN, DMF and DMSO (ΛM = 7 mho·cm2·mol–1, in 1 mM DMSO solution).
[Cu(flrx)(phen)Cl], 8: For the synthesis of complex 8, phen (45 mg, 0.25 mmol) was used as the N,N′-donor. Blue microcrystalline product of 8 (95 mg, 60%) was collected after a week. Anal. calc. for [Cu(flrx)(phen)Cl] (C29H25ClCuF3N5O3) (MW = 647.54). C: 53.79, H: 3.89, N: 10.81%; found: C: 53.55, H: 3.75, N: 11.04%. ESI–MS(+), m/z: found, 649.9; calc. for MW+1, 648.5. IR (KBr disk), νmax (cm−1): ν(C=O)pyr, 1620 (s); νasym(COO), 1587 (s); νsym(COO), 1371 (s); Δν(COO) = 216; ρ(C–H)phen, 724 (m). UV–vis: as nujol mull, λ (in nm): 670, 401; in DMSO, λ (in nm) (ε, in M−1 cm−1): 675 (65), 390 (sh) (250), 358 (sh) (1500), 329 (2700), 294 (8100). μeff at RT = 1.80 BM. The complex is soluble in MeOH, DMF and DMSO (ΛM = 4 mho·cm2·mol−1, in 1 mM DMSO solution) and partially soluble in CH3CN.
2.2.3. General Synthetic Procedure for Complexes [M(flrx)2(N,N′-Donor)2] (M(II) = Mn(II), Zn(II), Co(II), Ni(II), and N,N′-Donor = bipy, bipyam, phen) (Complexes 9–19)
The complexes of the formula [M(flrx)2(N,N′-donor)2] were prepared by the addition of a methanolic solution of fleroxacin (0.5 mmol, 185 mg), which was deprotonated by KOH (0.5 mmol, 0.5 mL 1 M) after 1 h stirring into a methanolic solution (5 mL) of MCl2 (0.25 mmol) at RT, simultaneously with a methanolic solution (5 mL) of the corresponding N,N′-donor (0.25 mmol). The reaction mixture was stirred for additional 30 min. After a few days, the (micro)crystalline product was formed and collected with filtration.
[Mn(flrx)2(bipy)], 9: For the synthesis of complex 9, ΜnCl2·4H2O (49 mg, 0.25 mmol) was used as the MCl2 and bipy (39 mg, 0.25 mmol) as the N,N′-donor. Beige crystals of 9 (120 mg, 50%) suitable for X-ray crystallography were collected after two months. Anal. calc. for [Mn(flrx)2(bipy)] (C44H42F6MnN8O6) (MW = 947.79). C: 55.76, H: 4.47, N: 11.88%; found: C: 55.50, H: 4.29, N: 11.69%. ESI–MS(+), m/z: found, 974.86. IR (KBr disk), νmax (cm−1): ν(C=O)pyr, 1618(s); νasym(COO), 1579 (s); νsym(COO), 1372 (s); Δν(COO) = 207; ρ(C–H)bipy, 760(m). UV–vis: as nujol mull, λ (in nm): 405 (sh); in DMSO, λ (in nm) (ε, in M−1 cm−1): 405 (sh) (190), 333 (3400), 286 (6800). μeff at RT = 5.95 BM. The complex is soluble in MeOH, DMF and DMSO (ΛM = 11 mho·cm2·mol–1, in 1 mM DMSO solution).
[Mn(flrx)2(bipyam)], 10: For the synthesis of complex 10, ΜnCl2·4H2O (49 mg, 0.25 mmol) was used as the MCl2 and bipyam (43 mg, 0.25 mmol) as the N,N′-donor. Yellowish microcrystalline product of 10 (120 mg, 50%) was collected after a month. Anal. calc. for [Mn(flrx)2(bipyam)] (C44H43F6MnN9O6) (MW = 962.81). C: 54.90, H: 4.50, N: 13.09%; found: C: 54.70, H: 4.59, N: 12.89%. ESI–MS(+), m/z: found, 992.01; calc. for MW + MeOH, 994.8. IR (KBr disk), νmax (cm−1): ν(C=O)pyr, 1616 (s); νasym(COO), 1574 (s); νsym(COO), 1372 (s); Δν(COO) = 202; ρ(C–H)bipyam, 762 (m). UV–vis: as nujol mull, λ (in nm): 402 (sh); in DMSO, λ (in nm) (ε, in M−1 cm−1): 390 (sh) (220), 316 (6500), 287 (6500). μeff at RT = 5.90 BM. The complex is soluble in DMF and DMSO (ΛM = 10 mho·cm2·mol–1, in 1 mM DMSO solution) and partially soluble in methanol.
[Mn(flrx)2(phen)], 11: For the synthesis of complex 11, ΜnCl2·4H2O (49 mg, 0.25 mmol) was used as the MCl2 and phen (45 mg, 0.25 mmol) as the N,N′-donor. Yellow product of 11 (135 mg, 55%) was collected after two months. Anal. calc. for [Mn(flrx)2(phen)] (C46H42F6MnN8O6) (MW = 971.82). C: 56.85, H: 4.36, N: 11.54%; found: C: 56.70, H: 4.22, N: 11.39%. ESI–MS(+), m/z: found, 1025.96. IR (KBr disk), νmax (cm−1): ν(C=O)pyr, 1616 (s); νasym(COO), 1578 (s); νsym(COO), 1372 (s); Δν(COO) = 206; ρ(C–H)phen, 731 (m). UV–vis: as nujol mull, λ (in nm): 405 (sh); in DMSO, λ (in nm) (ε, in M−1 cm−1): 395 (sh) (200), 357 (sh) (1900), 332 (3500), 285 (9500). μeff at RT = 5.92 BM. The complex is soluble in MeOH, DMF and DMSO (ΛM = 4 mho·cm2·mol−1, in 1 mM DMSO solution).
[Zn(flrx)2(bipy)], 12: For the synthesis of complex 12, ZnCl2 (34 mg, 0.25 mmol) was used as the MCl2 and bipy (39 mg, 0.25 mmol) as the N,N′-donor. Yellowish product of 12 (130 mg, 55%) suitable for X-ray crystallography were collected after a month. Anal. calc. for [Zn(flrx)2(bipy)] (C44H42F6N8O6Zn) (MW = 958.24). C: 55.15, H: 4.42, N: 11.69%; found: C: 55.30, H: 4.25, N: 11.49%. ESI–MS(+), m/z: found, 966.01. IR (KBr disk), νmax (cm−1): ν(C=O)pyr, 1619 (s); νasym(COO), 1578 (s); νsym(COO), 1372 (s); Δν(COO) = 206; ρ(C–H)bipy, 769 (m). UV–vis: as nujol mull, λ (in nm): 405 (sh); in DMSO, λ (in nm) (ε, in M−1 cm−1): 388(sh) (480), 332 (3500), 288 (7500). 1H NMR spectrum in DMSO-d6, δ (in ppm): 8.69 (4H, H2–flrx and H3,3′–bipy), 8.42 (2H, H6,6′–bipy), 7.99 (4H, H5–flrx and H5,5′–bipy), 7.50 (2H, H4,4′–bipy), 4.82– 4.73 (8H, H1b– and H1a–flrx), 3.25 (8H, H2′,6′–flrx), 2.40 (8H, H3′,5′–flrx), 2.19 (6H, H4′a–flrx). The complex is soluble in MeOH, DMF and DMSO (ΛM = 9 mho·cm2·mol−1, in 1 mM DMSO solution).
[Zn(flrx)2(bipyam)], 13: For the synthesis of complex 13, ZnCl2 (34 mg, 0.25 mmol) was used as the MCl2 and bipyam (43 mg, 0.25 mmol) as the N,N′-donor. Light-yellow product of 13 (130 mg, 50%) was collected after six weeks. Anal. calc. for [Zn(flrx)2(bipyam)] (C44H43F6N9O6Zn) (MW = 973.25). C: 54.30, H: 4.45, N: 12.95%; found: C: 54.50, H: 4.39, N: 12.79%. ESI–MS(+), m/z: found, 955.16. IR (KBr disk), νmax (cm−1): ν(C=O)pyr, 1616 (s); νasym(COO), 1578 (s); νsym(COO), 1372 (s); Δν(COO) = 206; ρ(C–H)bipyam, 775 (m). UV–vis: as nujol mull, λ (in nm): 406 (sh); in DMSO, λ (in nm) (ε, in M−1 cm−1): 392 (sh) (280), 323 (4100), 2+0 (6500). 1H NMR spectrum in DMSO-d6, δ (in ppm): 9.68 (1H, H1–bipyam), 8.73 (2H, H2–flrx), 8.20 (2H, H3,3′–bipyam), 7.69 (2H, H5–flrx), 7.61–7.67 (4H, H5,5′,6,6′–bipyam), 6.68 (2H, H4,4′–bipyam), 4.85–4.76 (8H, H1b– and H1a–flrx), 3.37 (8H, H2′,6′–flrx), 2.42 (8H, H3′,5′–flrx), 2.21 (6H, H4′a–flrx). The complex is soluble in DMF and DMSO (ΛM = 8 mho·cm2·mol−1, in 1 mM DMSO solution) and partially soluble in methanol.
[Zn(flrx)2(phen)], 14: For the synthesis of complex 14, ZnCl2 (34 mg, 0.25 mmol) was used as the MCl2 and phen (45 mg, 0.25 mmol) as the N,N′-donor. Off-yellow product of 14 (125 mg, 50%) was collected after two months. Anal. calc. for [Zn(flrx)2(phen)] (C46H42F6N8O6Zn) (MW = 982.26). C: 56.25, H: 4.31, N: 11.41%; found: C: 56.30, H: 4.05, N: 11.59%. ESI–MS(–), m/z: found, 978.92. IR (KBr disk), νmax (cm–1): ν(C=O)pyr, 1620 (s); νasym(COO), 1579 (s); νsym(COO), 1370 (s); Δν(COO) = 209; ρ(C–H)phen, 730 (m). UV–vis: as nujol mull, λ (in nm): 403 (sh); in DMSO, λ (in nm) (ε, in M−1 cm−1): 385 (sh) (190), 331 (2800), 288 (6400). 1H NMR spectrum in DMSO-d6, δ (in ppm): 9.06 (2H, H2,9–phen), 8.84 (2H, H4,7–phen), 8.70 (2H, H2–flrx), 8.23 (2H, H5,6–phen), 8.06 (2H, H3,8–phen), 7.32 (2H, H5–flrx), 4.81–4.73 (8H, H1b– and H1a–flrx), 3.22 (8H, H2′,6′–flrx), 2.38 (8H, H3′,5′–flrx), 2.18 (6H, H4′a–flrx). The complex is soluble in MeOH, DMF and DMSO (ΛM = 9 mho·cm2·mol−1, in 1 mM DMSO solution) and partially soluble in CH3CN and CH2Cl2.
[Co(flrx)2(bipy)], 15: For the synthesis of complex 15, CoCl2·6H2O (59 mg, 0.25 mmol) was used as the MCl2 and bipy (39 mg, 0.25 mmol) as the N,N′-donor. Orange product of 15 (120 mg, 50%) was collected after ten weeks. Anal. calc. for [Co(flrx)2(bipy)] (C44H42CoF6N8O6) (MW = 951.79). C: 55.53, H: 4.45, N: 11.77%; found: C: 55.30, H: 4.25, N: 11.59%. ESI–MS(+), m/z: found, 946.89. IR (KBr disk), νmax (cm–1): ν(C=O)pyr, 1621 (s); νasym(COO), 1578 (s); νsym(COO), 1372 (s); Δν(COO) = 207; ρ(C–H)bipy, 773 (m). UV–vis: as nujol mull, λ (in nm): 615 (sh), 522, 415 (sh); in DMSO, λ (in nm) (ε, in M−1 cm−1): 620 (sh) (15), 535 (25), 435 (sh) (55), 385 (sh) (130), 332 (3500), 287 (5900). μeff at RT = 3.98 BM. The complex is soluble in MeOH, DMF and DMSO (ΛM = 6 mho·cm2·mol−1, in 1 mM DMSO solution) and partially soluble in CH3CN and CH2Cl2.
[Co(flrx)2(bipyam)], 16: For the synthesis of complex 16, CoCl2·6H2O (59 mg, 0.25 mmol) was used as the MCl2 and bipyam (43 mg, 0.25 mmol) as the N,N′-donor. Orange product of 16 (135 mg, 55%) was collected after two months. Anal. calc. for [Co(flrx)2(bipyam)] (C44H43CoF6N9O6) (MW = 966.81). C: 54.66, H: 4.48, N: 13.04%; found: C: 54.40, H: 4.65, N: 12.89%. ESI–MS(+), m/z: found, 981.55. IR (KBr disk), νmax (cm−1): ν(C=O)pyr, 1620 (s); νasym(COO), 1579 (s); νsym(COO), 1372 (s); Δν(COO) = 207; ρ(C–H)bipyam, 773 (m). UV–vis: as nujol mull, λ (in nm): 602 (sh), 512, 420 (sh); in DMSO, λ (in nm) (ε, in M−1 cm−1): 615 (sh) (10), 515 (65), 430 (sh) (90), 382 (sh) (180), 323 (3400), 288 (7400). μeff at RT = 4.09 BM. The complex is soluble in MeOH, CH3CN, DMF and DMSO (ΛM = 9 mho·cm2·mol−1, in 1 mM DMSO solution).
[Co(flrx)2(phen)], 17: For the synthesis of complex 17, CoCl2·6H2O (59 mg, 0.25 mmol) was used as the MCl2 and phen (45 mg, 0.25 mmol) as the N,N′-donor. Orange product of 17 (125 mg, 50%) was collected after three months. Anal. calc. for [Co(flrx)2(phen)] (C46H42CoF6N8O6) (MW = 975.81). C: 56.62, H: 4.34, N: 11.48%; found: C: 56.40, H: 4.15, N: 11.29%. ESI–MS(+), m/z: found, 1045.93. IR (KBr disk), νmax (cm−1): ν(C=O)pyr, 1623 (s); νasym(COO), 1580 (s); νsym(COO), 1371 (s); Δν(COO) = 209; ρ(C–H)phen, 731 (m). UV–vis: as nujol mull, λ (in nm): 600, 524, 423 (sh); in DMSO, λ (in nm) (ε, in M–1 cm–1): 610 (sh) (15), 532 (55), 430 (sh) (85), 382 (sh) (195), 332 (4100), 287 (9100). μeff at RT = 3.95 BM. The complex is soluble in MeOH, CH3CN, DMF and DMSO (ΛM = 10 mho·cm2·mol−1, in 1 mM DMSO solution) and partially soluble in CH2Cl2.
[Ni(flrx)2(bipyam)], 18: For the synthesis of complex 18, NiCl2·6H2O (59 mg, 0.25 mmol) was used as the MCl2 and bipyam (43 mg, 0.25 mmol) as the N,N′-donor. Green microcrystalline product of 18 (120 mg, 50%) was collected after two months. Anal. calc. for [Ni(flrx)2(bipyam)] (C44H43F6N9NiO6) (MW = 966.58). C: 58.68, H: 4.48, N: 13.04%; found: C: 58.45, H: 4.65, N: 12.79%. ESI–MS(–), m/z: found, 965.52; calc. for MW–1, 965.6.IR (KBr disk), νmax (cm–1): ν(C=O)pyr, 1622 (s); νasym(COO), 1579 (s); νsym(COO), 1372 (s); Δν(COO) = 207; ρ(C–H)bipyam, 780 (m). UV–vis: as nujol mull, λ (in nm): 990, 620, 405 (sh); in DMSO, λ (in nm) (ε, in M–1 cm–1): 1000 (10), 607 (15), 415 (sh) (60), 324 (5600), 288 (8800); 10Dq = 10,000 cm–1, B = 705 cm–1, 10Dq/B = 14.2. μeff at RT = 3.05 BM. The complex is soluble in DMF and DMSO (ΛM = 12 mho·cm2·mol−1, in 1 mM DMSO solution) and partially soluble in methanol.
[Ni(flrx)2(phen)], 19: For the synthesis of complex 19, NiCl2·6H2O (59 mg, 0.25 mmol) was used as the MCl2 and phen (45mg, 0.25 mmol) as the N,N′-donor. Green microcrystalline product of 19 (125 mg, 50%) was collected after six weeks. Anal. calc. for [Ni(flrx)2(phen)] (C46H42F6N8NiO6) (MW = 975.59). C: 56.63, H: 4.34, N: 11.49%; found: C: 56.45, H: 4.11, N: 11.25%. ESI–MS(+), m/z: found, 996.28; calc. for MW+1 +H2O, 994.59. IR (KBr disk), νmax (cm−1): ν(C=O)pyr, 1615 (s); νasym(COO), 1578 (s); νsym(COO), 1372 (s); Δν(COO) = 206; ρ(C–H)phen, 730 (m). UV–vis: as nujol mull, λ (in nm): 985, 610, 402 (sh); in DMSO, λ (in nm) (ε, in M−1 cm−1): 1000 (10), 605 (10), 410 (sh) (80), 333 (3800), 287 (8500); 10Dq = 10,000 cm–1, B = 728 cm–1, 10Dq/B = 13.7. μeff at RT = 2.85 BM. The complex is soluble in MeOH, CH3CN, DMF and DMSO (ΛM = 8 mho·cm2·mol−1, in 1 mM DMSO solution) and partially soluble in CH2Cl2.