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C32H48NO2PRh, orthorhombic, P212121 (no. 19), a = 26.784(10) Å, b = 8.837(3) Å, c = 12.759(4) Å, V = 3020.0(18) Å3, Z = 4, Rgt(F) = 0.0400, wRref(F2) = 0.0920, T = 100(2) K.

C29H28O5PRe, triclinic, P1̄ (no. 2), a = 12.733(7) Å, b = 18.668(11) Å, c = 24.779(15) Å, α = 101.442(20)°, β = 100.844(18)°, γ = 104.240(19)°, V = 5419(9) Å3, Z = 8, Rgt(F) = 0.0307, wRref(F2) = 0.0772, T = 100 K.

C29H28O5PRe, monoclinic, P21/n (no. 14), a = 10.548(5) Å, b = 22.996(5) Å, c = 11.022(5) Å, β = 98.011(5)°, V = 2647.4(18) Å3, Z = 4, Rgt(F) = 0.0306, wRref(F2) = 0.0911, T = 100 K.

C27H24O5PRe, triclinic, P1̄ (no. 2), a = 9.0305(17) Å, b = 12.084(2) Å, c = 12.403(2) Å, α = 89.688(6)°, β = 70.083(6)°, γ = 76.315(6)°, V = 1232.2(4) Å3, Z = 2, Rgt(F) = 0.0180, wRref(F2) = 0.0432, T = 100(2) K.

C30H22N4O18Re2, monoclinic, P21/c (no. 14), a = 10.167(7) Å, b = 17.57(1) Å, c = 19.95(1) Å, β = 98.75(1)°, V = 3522(9) Å3, Z = 4, Rgt(F) = 0.0275, wRref(F2) = 0.0633, T = 100(2) K.

C43H34NO8PS2Re2, monoclinic, P21/c (no. 14), a = 12.165(8) Å, b = 19.027(11) Å, c = 18.848(14) Å, β = 108.735(2)°, V = 4131(5) Å3, Z = 4, Rgt(F) = 0.0308, wRref(F2) = 0.0683, T = 100(2) K.

C16H21O8N2F6Re, triclinic, P1̅, a = 9.161(5) Å, b = 10.283(5) Å, c = 12.974(5) Å, α = 87.739(5)°, β = 78.339(5)°, γ = 75.047(5)°, V = 1156.3(10) Å3, Z = 2, Rgt(F) = 0.037, wRref(F2) = 0.1012, T = 100(2) K.

C7H3N2O7, C8H20N, monoclinic, P21/n, a = 11.477(3) Å, b = 6.858(1) Å, c = 21.254(5) Å, β = 92.96(1)°, V = 1670.6(9) Å3, Z = 4, Rgt(F) = 0.0432, wRref(F2) = 0.1279, T = 100(2) K.

Two rhenium complexes, namely, fac‐tricarbonyl(triphenylphosphane‐κP)(tropolonato‐κ2O,O′)rhenium(I), [Re(C7H5O2)(C18H15P)(CO)3] or fac‐[Re(Trop)(PPh3)(CO)3] (1), and fac‐tricarbonyl(3,5,7‐tribromotropolonato‐κ2O,O′)(triphenylphosphane‐κP)rhenium(I), [Re(C7H2Br3O2)(C18H15P)(CO)3] or fac‐[Re(TropBr3)(PPh3)(CO)3] (2) (TropH is tropolone and and TropBr3H is tribromotropolone), were synthesized and their crystal and molecular structures confirmed by single‐crystal X‐ray diffraction. Both crystallized in the space group P and display an array of inter‐ and intramolecular interactions which were confirmed by solid‐state 13C NMR spectroscopy using cross polarization magic angle spinning (CPMAS) techniques, as well as Hirshfeld surface analysis. The slightly longer Re—P distance of 1 [2.4987 (5) versus 2.4799 (11) Å for 1 and 2, respectively] suggests stronger back donation from the carbonyl groups in the former case, possibly due to the stronger electron‐donating ability of the unsubstituted tropolonate ring system. However, this is not supported in the Re—CO bond distances of 1 and 2. [ABSTRACT FROM AUTHOR]

Two bidentate PNP ligands N,N-bis(di-p-tolylphosphino)cyclohexylamine (Cy-pTolPNP) (1) and N,N-bis(di-p-tolylphosphino)cyclobutylamine (Cb-pTolPNP) (2) were synthesized and crystallized. Coordination to the fac-[MI(CO)3]+ core (M = Re, 99Tc) yielded fac-[Re(Cy-pTolPNP)(CO)3Br] (1A), fac-[99Tc(Cy-pTolPNP)(CO)3Cl] (1B), fac-[Re(Cb-pTolPNP)(CO)3Br] (2A) and fac-[99Tc(Cb-pTolPNP)(CO)3Cl] (2B) in relatively good yields (56 to 86%): The structures of 1, 2, 1A and 1B were studied by single crystal X-ray crystallography. Preliminary mitochondrial/antimicrobial evaluation of the free ligand (N,N-bis(di-p-tolylphosphino)-cyclohexylamine) (1) and its respective fac-[Re(CO)3]+ (1A) complex indicates that neither the free ligand nor the complex was active against selected fungi Eremothecium ashbyii and Nadsonia fulvescens. In addition, all four compounds were found to have no activity against Gram-positive and Gram-negative bacterial species. These biological results are essential to the understanding of how these types of complexes behave and show they are perfectly stable in the evaluated bio-environments. The results also indicate that these ligands and complexes may present themselves as excellent models for radiotoxicity studies using technetium-99m, but more specifically, rhenium Re-186 and Re-188. [ABSTRACT FROM AUTHOR]

The title compound, 2-(methylamino)cyclohepta-2,4,6-trien-1-one, C8H9NO, crystallizes in the monoclinic space group P21/c, with three independent molecules in the asymmetric unit. The planarity of the molecules is indicated by planes fitted through the seven ring carbon atoms. Small deviations from the planes, with an extremal r.m.s. deviation of 0.0345 Å, are present. In complexes of transition metals with similar ligands, the large planar seven-membered aromatic rings have shown to improve the stability of the complex. Two types of hydrogen-bonding interactions, C--H···O and N--H···O, are observed, as well as bifurcation of these interactions. The N--H···O interactions link molecules to form infinite chains. The packing of molecules in the unit cell shows a pattern of overlapping aromatic rings, forming column-like formations. π-π interactions are observed between the overlapping aromatic rings at 3.4462 (19) Å from each other. [ABSTRACT FROM AUTHOR]

Methanol substitution in the fac-[Re(CO)3(Trop)(MeOH)] complex (Trop− = tropolonate) was studied with a range of seven nucleophiles, namely pyridine (Py), 4-dimethylaminopyridine (DMAP), imidazole (Im), thiourea (TU), 1-methyl-2-thiourea (MeTU), bromide (Br−) and iodide (I−) at variable temperature, and at ambient and high pressure. The substitution products were characterized by NMR, IR and UV/vis spectroscopy, and by chemical analysis, and the crystal structures of two of these, namely fac-[Re(Trop)(CO)3(Im)] and fac-[Re(Trop)(CO)3(DMAP)], are reported. High-pressure kinetic studies with four of these entering nucleophiles in methanol at 25 °C on fac-[Re(Trop)(CO)3(MeOH)] yielded the following activation volumes, ΔV≠(kL), for the ligation by four nucleophiles as defined by kL (cm3 mol−1): Im: 9.0 ± 0.2; Py: 10.1 ± 0.2; TU: 10.0 ± 0.3 and MeTU: 14.5 ± 0.3. Since these experimental ΔV≠(kL) values were positive but smaller than expected, it was interpreted that these indicated a dissociative/dissociative interchange pathway for these substitution reactions. Kinetic studies at ambient pressure and variable temperature in methanol on fac-[Re(Trop)(CO)3(MeOH)] with a range of eight entering nucleophiles pointed more clearly to a dissociative pathway and yielded the following results, wherein a clear linear free-energy relationship (LFER) was established for the entering nucleophiles Py, DMAP, Im, TU, MeTU, NCS−, Br− and I−, within the following ranges: kL (ligation; M−1 s−1), 0.263 ± 0.001 to 0.765 ± 0.002; k−L (solvolysis; s−1), (0.07 ± 0.01) × 10−3 to 0.674 ± 0.001; KL (equilibrium; M−1); 1.06 ± 0.01 to 2000 ± 500; ΔH≠(kL) (kJ mol−1), 58.0 ± 0.7 to 76.1 ± 0.6, and ΔS≠(kL) (J K−1 mol−1); −55 ± 2 to 6 ± 3. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of two dinuclear complexes, namely fac‐hexacarbonyl‐1κ3C,2κ3C‐(pyridine‐1κN)[μ‐2,2′‐sulfanediyldi(ethanethiolato)‐1κ2S1,S3:2κ3S1,S2,S3]dirhenium(I), [Re2(C4H8S3)(C5H5N)(CO)6], (1), and tetraethylammonium fac‐tris(μ‐2‐methoxybenzenethiolato‐κ2S:S)bis[tricarbonylrhenium(I)], (C8H20N)[Re2(C7H7OS)3(CO)6], (2), together with two mononuclear complexes, namely (2,2′‐bithiophene‐5‐carboxylic acid‐κ2S,S′)bromidotricarbonylrhenium(I), (3), and bromidotricarbonyl(methyl benzo[b]thiophene‐2‐carboxylate‐κ2O,S)rhenium(I), (4), are reported. Crystals of (1) and (2) were characterized by X‐ray diffraction. The crystal structure of (1) revealed two Re—S—Re bridges. The thioether S atom only bonds to one of the ReI metal centres, while the geometry of the second ReI metal centre is completed by a pyridine ligand. The structure of (2) is characterized by three S‐atom bridges and an Re…Re nonbonding distance of 3.4879 (5) Å, which is shorter than the distance found for (1) [3.7996 (6)/3.7963 (6) Å], but still clearly a nonbonding distance. Complex (1) is stabilized by six intermolecular hydrogen‐bond interactions and an O…O interaction, while (2) is stabilized by two intermolecular hydrogen‐bond interactions and two O…π interactions. [ABSTRACT FROM AUTHOR]