In vitro investigation of mammalian early embryonic development.

Mammalian embryonic development starts from a fertilized egg, which cleaves to form morula and blastocyst. At the same time, the early embryo is transported from the fallopian tube to the uterus for implantation. After implantation, the embryo undergoes gastrulation and forms a gastrula, further developing a new individual. The development of embryo in the uterus causes the difficulties in sampling and observation, hindering the understanding of mammalian embryonic development. Therefore, it is necessary to develop the technology to overcome the barrier of in vivo embryonic development. In December 2021, "Embryo 'husbandry' opens windows into early development" was selected as one of Science's 2021 breakthroughs. This review focuses on the achievements of in vitro mammalian embryos and discusses their limitations and the future applications for the investigation of mammalian embryonic development and human related diseases.

Inorganic Ferrocene Analogue [Fe(P4)2]2.

Inorganic metallocene derivatives containing only cyclo-Pn ligands have been targeted for more than 20 years, but their syntheses have never been achieved by pursuing the conventional route of using P4 phosphorus except for the generation of [Ti(η5-P5)2]2-. Herein, we report a facile one-step method for the synthesis of the homoleptic iron complex [Fe(P4)2]2- by the Zintl-phase-type precursor KP. 31P NMR analyses indicate that upon dissolving the KP phase in ethylenediamine P42- was generated only in the presence of 2,2,2-crypt. The amounts of cation-sequestering agents, the type of iron precursor, and their consuming ratio have a decisive impact on the yield of [Fe(P4)2]2-. Both the FeII and the FeIII precursors can oxidize P42- to give a concomitant product [(P7)Fe(P4)]3-, which can be partially inhibited by the addition of potassium to produce relatively pure crystalline [K(2,2,2-crypt)]2[Fe(P4)2].

A sandwich-type cluster containing Ge@Pd3 planar fragment flanked by aromatic nonagermanide caps.

Sandwich-type clusters with the planar fragment containing a heterometallic sheet have remained elusive. In this work, we introduce the [K(2,2,2-crypt)]4{(Ge9)2[η6-Ge(PdPPh3)3]} complex that contains a heterometallic sandwich fragment. The title compound is structurally characterized by means of single-crystal X-ray diffraction, which reveals the presence of an unusual heteroatomic metal planar fragment Ge@Pd3. The planar fragment contains a rare formal zerovalent germanium core and a peculiar bonding mode of sp2-Ge@(PdPPh3)3 trigonal planar structure, whereas the nonagermanide fragments act as capping ligands. The chemical bonding pattern of the planar fragment consists of three 2c-2e Pd-Ge σ-bonds attaching Pd atoms to the core Ge atom, while the binding between the planar fragment and the aromatic Ge9 ligands is provided by six 2c-2e Pd-Ge σ-bonds and two delocalized 4c-2e σ-bonds. The synthesized cluster represents a rare example of a sandwich compound with the heteroatomic metal planar fragment and inorganic aromatic capping ligands.

σ-Aromaticity-Induced Stabilization of Heterometallic Supertetrahedral Clusters [Zn6 Ge16 ]4- and [Cd6 Ge16 ]4.

In this work, the largest heterometallic supertetrahedral clusters, [Zn6 Ge16 ]4- and [Cd6 Ge16 ]4- , were directly self-assembled through highly-charged [Ge4 ]4- units and transition metal cations, in which 3-center-2-electron σ bonding in Ge2 Zn or Ge2 Cd triangles plays a vital role in the stabilization of the whole structure. The cluster structures have an open framework with a large central cavity of diameter 4.6 Šfor Zn and 5.0 Šfor Cd, respectively. Time-dependent HRESI-MS spectra show that the larger clusters grow from smaller components with a single [Ge4 ]4- and ZnMes2 units. Calculations performed at the DFT level indicate a very large HOMO-LUMO energy gap in [M6 Ge16 ]4- (2.22 eV), suggesting high kinetic stability that may offer opportunities in materials science. These observations offer a new strategy for the assembly of heterometallic clusters with high symmetry.

All-metal σ-antiaromaticity in dimeric cluster anion {[CuGe9Mes]2}4.

In this work, we report a dimeric cluster anion, {[CuGe9Mes]2}4-, which was isolated as the [K(2,2,2-crypt)]+ salt and characterized by using single-crystal X-ray diffraction and ESI mass spectroscopy. The title cluster represents the first locally σ-antiaromatic compound in the solid state, as well as the first heteroatomic antiaromatic compound.

A fast and highly selective Congo red adsorption material based on a cadmium-phosphonate network.

In this work, a cadmium-phosphonate network was prepared based on a tetrahedral shaped tetraphosphonic acid linker. The resulting three-dimensional compound Cd4(H4L)2(phen)2(H2O)4 (1) exhibited a rapid and efficient adsorption of Congo red (CR) dye, the adsorption capacity of which reached 684 mg g-1. Furthermore, this adsorbent showed excellent structural stability and adsorptive recyclability after three times of adsorption and desorption. The absorption kinetics fitted well with the pseudo-second-order kinetic model, revealing that the adsorption of the cadmium-phosphonate compound undergoes a chemical process, where hydrogen bonding between the amide groups (from CR) and the uncoordinated phosphonate oxygen atoms of the compound plays a pivotal role.

Structural isomerism in the [(Ni@Sn9)In(Ni@Sn9)]5- Zintl ion.

A new Zintl cluster, [(Ni@Sn9)In(Ni@Sn9)]5-, has been isolated in two distinct isomeric forms, one where both Ni@Sn9 units are coordinated to the bridging In atom in an η3- mode, the other where one is η3- and the other η4-. Density functional theory indicates that the energetic separation between these two structures is minimal, suggesting that crystal packing plays a decisive role in the structural chemistry. A comparison of the electronic structure of [(Ni@Sn9)In(Ni@Sn9)]5- with [(Ni@Ge9)Ni(Ni@Ge9)]4-, which has four fewer valence electrons, sheds some light on possible mechanisms that lead to the fusion of cluster fragments.