The semen quality among young Chinese men has declined over a period of 15 years, especially in terms of sperm concentration, total sperm count, sperm progressive motility, and normal morphology.

In this paper, using a simple method, 17 isostructural polyoxotitanates (POTs) were synthesized, including the pristine [Ti12O16(O(i)Pr)16], the monodefected [Ti11O13(O(i)Pr)18], and the heterometal-doped [Ti11O14(O(i)Pr)17(ML)] (M = Mg, Ca, Zn, Cd, Co, or Ni; L = Cl, Br, I, or NO3). The electronic structures of these POTs were determined by UV-vis spectroscopy and DFT calculations. Upon UV irradiation of the POTs, electron spin resonance showed the formation of Ti(III) under anaerobic conditions and superoxide (O2(•-)) in the presence of O2. The photoactivities of the POTs were then probed with Ti(III) production and short-circuit photocurrent experiments. The photophysical processes were studied using steady-state and transient photoluminescence. The results show that within the very similar structures, the deexcitation processes of the photoexcited POTs can be greatly affected by the dopants, which result in enhanced or decreased photoactivities. Co and Ni doping enhances the absorption of the visible light accompanied by serious loss of UV photoactivities. On the other hand, a Ti vacancy (in [Ti11O13(O(i)Pr)18]) does not reduce the band gap of a POT but improves the UV photoactivities by serving as surface reaction site. The POTs were then used as molecular models of titanium oxide nanoparticles to understand some important issues relevant to doped titanate, i.e., coordination environment of the dopant metal, electronic structure, photoactivities, and photophysical processes. Our present findings suggest that for solar energy harvesting applications of titanium oxides like photocatalysis and solar cells substitution of titanium atoms by transition metal ions (like Co and Ni) to extend the absorption edges may not be an efficient way, while loading of Ti vacancies is very effective.

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During solvothermal alcoholysis of a mixture of TiI4 and Ti(O(i)Pr)4, a {I@Ti22} cage cluster encapsulating an OH and iodide guests is crystallized. The {I@Ti22} host-guest cluster surface is postfunctionalizable with catecholate and carboxylate ligands. The synthetic details, structural characterization, spectroscopic properties of the obtained cages clusters are provided. The present study provides candidates for modeling ligand exchange and electron-hole transfer at the titanate nanoparticle surface, and meanwhile offers new opportunities for understanding the TiO2 nanocrystalline formation in solvothermal processes.

Linear A–D–A or A−π–D−π–A architectures are predominant in the design of promising nonfullerene acceptors (NFAs), which promoted the rapid progress of organic solar cells. However, utilization of four electron-accepting units (A) to construct four-armed NFAs is rarely reported and the relationship of structure–properties–performance is unclear. In this study, we designed and synthesized a novel acceptor (A401) with an (AA)−π–D−π–(AA) configuration, where four 1,1-dicyanomethylene-3-indanone groups were used as the end-capped segments. When A401 was paired with a classic p-type polymer PBDB-T, a power conversion efficiency of 7.54% could be achieved, which was much higher than that of the reported two-armed analogue of DC-IDT-2T (3.93%). The improved photovoltaic performance of A401 should be ascribed to the high electron affinity. Our results indicate introducing more end-capped electron-accepting units is a simple and effective alternative strategy for the design of promising NFAs. Our conceptualized molecular architecture will encourage further research of high-performance multiarmed NFAs.

A set of titanium oxide clusters (TOCs) comprised of 4 to 16 Ti atoms are synthesized with substituted salicylates (SSAs). The interfacial coordination environment of these SSA/Ti oxide hybrids are surveyed and found to be limited to four binding modes, with the bridging chelate mode being the most common one. The SSA‐functionalized TOCs show strong visible light absorption properties. The contribution of the SSAs in the frontier orbitals of the TOCs are analyzed by using TD‐DFT calculations based on the molecular geometries determined by X‐ray diffraction. For TOCs of relatively high O/Ti ratio, the SSAs narrow the band gap of the TOCs by contributing solely to the HOMOs. Both binding modes and locations of the SSAs are important for the roles of SSAs in changing the HOMOs and thereby the absorption onsets.

The functionalization of Ti17O24(OiC3H7)20 (Ti17) with substituted catechols is studied by using crystallography, Raman spectroscopy, and stopped‐flow kinetics. The knowledges on the number of accessible functionalities, their exact location correlated with their Raman assignment, and the kinetic parameters are acquired. A catecholate ligand binds to a five‐coordinated surface Ti of Ti17 (denoted as Tia site) adopting the mono‐protonated, chelate‐bidentate binding mode, whereas it binds to a six‐coordinated surface‐Ti (denoted as Tib site) adopting the mono‐dentate mode. With low numbers of equivalents of added catechols the Tia sites show higher reactivity than the Tib sites toward functionalization. Two binding modes may co‐exist and equilibrate in solution. Our results also imply that at most eight of the twenty OiC3H7 ligands of Ti17 are exchangeable without damage of the core structure. The kinetic studies point out that the ligand‐exchange reaction is second order and occurs very fast. The current findings are helpful for the controlled functionalization of Ti17 and other Ti oxide clusters, and the further application of them as building blocks in supramolecular chemistry for the assembly of well‐defined organic–inorganic hybrid materials.