Facile high yield, excellent catalytic performance of polyoxometalate-based lanthanide phosphine oxide complexes: Syntheses, structures, photocatalysis and THz spectra.

Water pollution, which continuously threatens human health and the sustainable development of society, has become a major concern. Photocatalytic degradation is an effective strategy to remove organic dyes from wastewater. For this strategy, it is crucial to select the appropriate catalyst. Using triphenylphosphine oxide (OPPh3) as the ligand, phosphomolybdic acid as the anion template, three new lanthanide complexes [Ln(OPPh3)4(H2O)3](PMo12O40)∙4C2H5OH (1-3) (Ln = Sm, Gd, Tb) were synthesized. The raw materials for the reaction are cheap and readily available. The convenient synthesis method is environmentally friendly, with high yield (70%-80%). Complexes 1-3 are all seven-coordinated mononuclear structures centered on lanthanide ions, [PMo12O40]3- anions and solvent molecules are not coordinated with metal ions. These mononuclear structures eventually form complicated 3D supramolecular structures through hydrogen bonds, Mo-O … π or C-H … π weak interactions. Complexes 1-3 photocatalytic degradation of MB have high removal rates, as catalysts have enough stability to be reused, and can be used as excellent catalysts for the degradation of dye molecules in sewage. Among them, the removal rate of MB by photodegradation of complex 2 was highest (99.50%). In addition, the effects of different initial concentrations of MB solution and different types of organic dyes on the photocatalysis experiment were investigated. The photocatalytic reaction mechanism of complexes 1-3 was also studied. Due to the similar structures of complexes 1-3, they have almost the same THz absorption spectra with different absorption intensity, which may be attributed to the difference of the number of weak interactions. Therefore, terahertz spectroscopy can be used as a sensitive method to distinguish and determine small differences between lanthanide-organic complexes. This is the first time that this spectrum has been used to characterize lanthanide phosphine oxide complexes modified by [PMo12O40]3-.

Intermolecular interactions, photocatalysis and THz-TDS interrelationships for lanthanide phosphine oxide complexes based on {PW12}.

A series of rare earth complexes containing (α-PW12O40)3- and PO ligand are synthesized by water bath in 70 °C, [Ln(OPPh3)4(H2O)3](PW12O40)·4CH3CN (Ln = La, Pr, Nd, Sm, Gd, Tb, Ho 1-7) (OPPh3 = Triphenylphosphine oxide, {PW12} = phosphotungstic acid). The precise structures are confirmed by X-ray single crystal diffraction and the result shows all complexes are isostructural. Complexes 1-7 are fully characterized by PXRD, FT-IR, TGA, UV diffuse reflectance spectra and terahertz time-domain spectroscopy (THz-TDS). Complex 3 exhibits the highest photocatalytic degradation efficiency for methylene blue (MB) in this series of complexes. The experimental results showed that the photodegradation efficiency can remain constant at the level of 95% after five consecutive cycles. The photocatalytic reaction kinetics and mechanism of complexes were investigated. Additionally, complexes also exhibit photocatalytic hydrogen evolution activity. THz-TDS was used to characterize the complexes and its raw materials, the characteristic peaks of OPPh3 (broad peak at 1.20 THz) and phosphotungstic acid (sharp peaks at 0.23, 0.32 THz) were obtained.

Two-Coordinate Copper(I)/NHC Complexes: Dual Emission Properties and Ultralong Room-Temperature Phosphorescence.

As a kind of photoluminescent material, CuI complexes have many advantages such as adjustable emission, variable structures, and low cost, attracting attention in many fields. In this work, two novel two-coordinate CuI -N-heterocyclic carbene complexes were synthesized, and they exhibit unique dual emission properties, fluorescence and phosphorescence. The crystal structure, packing mode, and photophysical properties under different conditions were systematically studied, proving the emissive mechanism to be the locally excited state of the carbazole group. Based on this mechanism, ultralong room-temperature phosphorescence (RTP) with a lifetime of 140 ms is achieved by selective deuteration of the carbazole group. These results deepen the understanding of the luminescence mechanism and design strategy for two-coordinate CuI complexes, and prove their potential in applications as ultralong RTP materials.

Stimulus-Responsive Copper Complex Nanoparticles Induce Cuproptosis for Augmented Cancer Immunotherapy.

Cuproptosis, an emerging form of programmed cell death, has received tremendous attention in cancer therapy. However, the efficacy of cuproptosis remains limited by the poor delivery efficiency of copper ion carriers. Herein, copper complex nanoparticles (denoted as Cu(I) NP) are developed that can efficiently deliver copper complex into cancer cells to induce cuproptosis. Cu(I) NP demonstrate stimulus-responsive release of copper complexes, which results in mitochondrial dysfunction and promotes the aggregation of lipoylated dihydrolipoamide S-acetyltransferase (DLAT), leading to cuproptosis. Notably, Cu(I) NP not only induce cuproptosis, but also elicit robust immune responses to suppress tumor growth. Overall, this study provides a promising strategy for cuproptosis-based cancer therapy.

6-Nitro-1,3-benzothia-zole-2(3H)-thione.

In the title mol-ecule, C(7)H(4)N(2)O(2)S(2), the nitro group is twisted by 5.5 (1)° from the plane of the attached benzene ring. In the crystal, N-H⋯S hydrogen bonds link pairs of mol-ecules into inversion dimers, which are linked by weak C-H⋯O inter-actions into sheets parallel to (101). The crystal packing exhibits short inter-molecular S⋯O contacts of 3.054 (4) Šand π-π inter-actions of 3.588 (5) Šbetween the centroids of the five- and six-membered rings of neighbouring mol-ecules.

Development of stimuli responsive polymeric nanomedicines modulating tumor microenvironment for improved cancer therapy.

The complexity of the tumor microenvironment (TME) severely hinders the therapeutic effects of various cancer treatment modalities. The TME differs from normal tissues owing to the presence of hypoxia, low pH, and immune-suppressive characteristics. Modulation of the TME to reverse tumor growth equilibrium is considered an effective way to treat tumors. Recently, polymeric nanomedicines have been widely used in cancer therapy, because their synthesis can be controlled and they are highly modifiable, and have demonstrated great potential to remodel the TME. In this review, we outline the application of various stimuli responsive polymeric nanomedicines to modulate the TME, aiming to provide insights for the design of the next generation of polymeric nanomedicines and promote the development of polymeric nanomedicines for cancer therapy.

4,4'-Bipyridine-3,3'-disulfanediyl-bis-(1H-1,2,4-triazole-5-amine) (1/1).

In the title 1:1 adduct, C(10)H(8)N(2)·C(4)H(6)N(8)S(2)·, the components are connected through N-H⋯N hydrogen bonds, leading to a two-dimensional structure. The C-S-S-C torsion angle is -83.6 (1)°. The dihedral angle between pyridine rings is 1.86 (15)°.

4,4'-Bipyridine-1,1'-diium bis-(1,3-benzo-thia-zole-2-thiol-ate).

In the title salt, C10H10N2(2+)·2C7H4NS2(-), the complete 4,4'-bipyridine-1,1'-diium dication is generated by a center of symmetry. In the crystal, N-H⋯N hydrogen bonds are observed between the cations and anions.

Iodido[5-methyl-1H-benzimidazole-2(3H)-thione-κS]bis-(triphenyl-phosphane-κP)copper(I) methanol monosolvate.

In the title compound, [CuI(C(8)H(8)N(2)S)(C(18)H(15)P)(2)]·CH(3)OH, the coordination environment around the Cu(I) atom is distorted tetra-hedral, defined by two P atoms of two triphenyl-phosphane ligands, one S atom of a 5-methyl-1H-benzimidazole-2(3H)-thione ligand and one I atom. The complex mol-ecules and the methanol solvent mol-ecules are connected via N-H⋯O and O-H⋯I hydrogen bonds, forming a chain along [010]. An intra-molecular N-H⋯I hydrogen bond is also observed.

3-Amino-1H-1,2,4-triazole-5(4H)-thione-4,4'-bipyridine (1/1).

The title two-component mol-ecular crystal, C(10)H(8)N(2)·C(2)H(4)N(4)S, was obtained unexpectedly by reaction of Zn(NO(3))(2)·6H(2)O, NH(4)BF(4) with 3-amino-1,2,4-triazole-5-thione (3-AMT) and 4,4'-bipyridine in water. The dihedral angle between the pyridine rings in the 4,4'-bipyridine molecule is 17.00 (13)°. In the crystal, N-H⋯N and N-H⋯S hydrogen bonds between the components lead to the formation of a three-dimensional network. Furthermore, the structure features face-to-face π-π stacking inter-actions between the 4,4'-bipyridine and triazole rings, with a centroid-centroid distance of 2.976 (2) Å.

[Bis[µ-bis-(diphenyl-phosphino)methane-1:2κ(2)P:P']-bis-(nitrito-κ(2)O,O')]disilver(I) acetonitrile disolvate.

The title complex, [Ag(2)(NO(2))(2)(C(25)H(22)P(2))(2)]·2CH(3)CN, is a centrosymmetric dimer in which two bis(diphenylphosphino)methane ligands bridge two Ag(+) ions, forming an eight-membered ring with a short Ag⋯Ag separation of 3.1809 (5) Å. The distorted P(2)O(2) coordination of the cation is completed by two O-donors from a symmetric bidentate chelate NO(2) (-) anion [Ag-O = 2.550 (3) and 2.567 (3) Å].

5,6-Dimethyl-1,2,4-triazin-3-amine.

In the crystal structure of the title compound, C(5)H(8)N(4), adjacent mol-ecules are connected through N-H⋯N hydrogen bonds, resulting in a zigzag chain along [100]. The amino groups and heterocyclic N atoms are involved in further N-H⋯N hydrogen bonds, forming R(2) (2)(8) motifs.

Tetra-kis(triphenyl-phosphane-κP)silver(I) tetra-fluorido-borate.

The title complex, [Ag(C(18)H(15)P)(4)]BF(4), was prepared by the reaction of silver(I) tetra-fluorido-borate and triphenyl-phosphane in the presence of 1,2-bis-(pyridin-2-yl)ethyl-ene. The Ag(I) atom is tetra-hedrally coordinated by four P atoms from triphenyl-phosphane (PPh(3)) ligands. Due to symmetry, the tetra-fluorido-borate anion is disordered over three positions (each with one third occupancy). The tetra-fluorido-borate anion does not coordinate to the Ag(I) atom.

catena-Poly[[(isoquinoline-κN)(triphenylphospane-κP)copper(I)]-µ-thio-cyanato-κN:S].

In the title coordination compound, [Cu(NCS)(C(9)H(7)N)(C(18)H(15)P)](n), the Cu(I) atom is tetra-hedrally coordinated by one N atom from an isoquinoline ligand, one P atom from a triphenyl-phospane ligand, and one N and one S atom from two thio-cyanate anions. The thio-cyanide anions bridge the Cu(I) atoms into a chain along [100]. π-π inter-actions between the pyridine and benzene rings of the isoquinoline ligands connect the chains [centroid-to-centroid distance = 3.722 (3) Å].

Bis[µ-bis-(diphenyl-phosphan-yl)methane-κ(2)P:P']bis-[(isoquinoline-κN)silver(I)] bis-(trifluoro-methane-sulfonate)-isoquinoline (1/1).

The title complex, [Ag(2)(C(25)H(22)P(2))(2)(C(9)H(7)N)(2)](CF(3)SO(3))(2)·C(9)H(7)N, was prepared by the reaction of silver(I) trifluoro-methane-sulfonate with isoquinoline and bis-(diphenyl-phosphan-yl)methane (dppm). The dinuclear mol-ecule is located about a center of inversion and the Ag(I) atom is coordinated by two dppm P atoms and one isoquinoline N atom, forming an eight-membered metalla ring. In addition, in the asymmetric unit, there is a half-mol-ecule of isoquinoline located about a center of inversion. Since this mol-ecule does not possess this symmetry, for one position in the ring there is superposition of both a C atom of a C-H group and the isoquinoline N atom. In the structure, the Ag-P distances [2.4296 (9) and 2.4368 (9) Å] agree with the corresponding distances in related structures, while the Ag-N bond length [2.489 (3) Å] is slightly longer than that in related structures. On the other hand, the P-Ag-P angle [156.44 (3)°] is much larger than the corresponding angles in related structures. The trifluoro-methane-sulfonate anions do not coordinate to Ag(I) atoms. As is usually found for these anions, the -CF(3) group is disordered over two orientations [occupancies = 0.57 (12) and 0.43 (12)].

catena-Poly[[[diaqua-(1,10-phenanthroline-κ(2)N,N')zinc]-µ-4,4'-bipyridine-κ(2)N:N'] dinitrate 4,4'-bipyridine hemisolvate monohydrate].

In the title compound, [Zn(C(10)H(8)N(2))(C(12)H(8)N(2))(H(2)O)(2)](NO(3))(2)·0.5C(10)H(8)N(2)·H(2)O, the Zn(II) atom is coordinated in a distorted octa-hedral geometry by two N atoms from two 4,4'-bipyridine (4,4'-bipy) ligands, two N atoms from a chelating 1,10-phenanthroline ligand and two O atoms from two mutually cis water mol-ecules. The 4,4'-bipy ligands bridge the Zn(II) atoms into a chain structure along [100]. The uncoordinated 4,4'-bipy mol-ecule lies on an inversion center. O-H⋯O and O-H⋯N hydrogen bonds connect the cationic chains, the nitrate anions, the uncoordinated 4,4'-bipy mol-ecules and the water mol-ecules into tow-dimensional networks.

Tetra-kis(triphenyl-phosphane-κP)silver(I) trifluoro-methane-sulfonate dichloro-methane monosolvate.

In the title compound, [Ag(C(18)H(15)P)(4)]CF(3)O(3)S·CH(2)Cl(2), the Ag atom is coordinated by four P atoms from four PPh(3) ligands. The P-Ag-P angles are in the range 108.02 (6)-110.15 (6)°, which confirms the distorted tetra-hedral environment around the Ag atom.

Tris(3-amino-5,6-dimethyl-1,2,4-triazine-κN)silver(I) trifluromethane-sulfonate-3-amino-5,6-dimethyl-1,2,4-triazine (1/1).

The asymmetric unit of the title compound, [Ag(C(5)H(8)N(4))(3)](CF(3)O(3)S)·C(5)H(8)N(4), contains two cations, two anions and two uncoordinated 3-amino-5,6-dimethyl-1,2,4-triazine (admt) ligands. It was prepared from the reaction of silver trifluoro-methane-sulfonate and admt in a 2:3 molar ratio. Both silver(I) ions are bonded to three admt mol-ecules via their 2-position triazine N atoms in almost regular trigonal-planar geometries. Three intra-molecular N-H⋯N hydrogen bonds between adjacent admt mol-ecules in each cation help to maintain their overall near planarities (r.m.s. deviations for the 28 non-H atoms = 0.139 and 0.153 Å). In the crystal, numerous N-H⋯N, N-H⋯O, C-H⋯O, C-H⋯N and C-H⋯F hydrogen-bonding interactions link the components into a three-dimensional network.

Poly[bis-[µ-1,3-bis-(diphenyl-phosphan-yl)propane-κP:P']-di-µ-thio-cyanato-κS:N;κN:S-disilver(I)].

In the title coordination polymer, [Ag(2)(NCS)(2)(C(27)H(26)P(2))(2)](n), two centrosymmetrically related Ag(+) cations are linked by two thio-cyanate anions into binuclear eight-membered macrocycles. The Ag⋯Ag separation within the macrocycle is 5.4400 (6) Å. The distorted tetra-hedral coordination about each metal atom is completed by the P atoms of two bridging 1,3-bis-(diphenyl-phosphan-yl)propane ligands, forming polymeric ribbons parallel to the a axis.

Tris(2,2'-bi-1H-imidazole-κN,N)-nickel(II) dinitrate N,N-dimethyl-formamide monosolvate.

The reaction of nickel salts and 4,4'-bipyridine with 2,2'-bi-imidazole (H(2)biim) yielded the title complex, [Ni(C(6)H(6)N(4))(3)](NO(3))(2)·C(3)H(7)NO. The Ni(II) atom is chelated by three H(2)biim ligands in a distorted octa-hedral coordination geometry. The two nitrate anions and one dimethyl-formamide (DMF) mol-ecule are not coordinated. The compound has a three-dimensional structure, formed by extensive hydrogen bonding between [Ni(H(2)biim)(3)](2+) cations and nitrate anions, each nitrate anion forming hydrogen bonds with an R(1) (2)(4) motif. The DMF molecule is disordered over three sets of sites, with occupancy ratios of 0.341 (16):0.350 (17):0.309 (19).