Recent development in the synthesis and characterization of noble-gas compounds is reviewed, i.e., noble-gas chemistry reported in the last five years with emphasis on the publications issued after 2017. XeF2 is commercially available and has a wider practical application both in the laboratory use and in the industry. As a ligand it can coordinate to metal centers resulting in [M(XeF2)(x)](n+) salts. With strong Lewis acids, XeF2 acts as a fluoride ion donor forming [XeF](+) or [Xe2F3](+) salts. Latest examples are [Xe2F3][RuF6]center dot XeF2, [Xe2F3][RuF6] and [Xe2F3][IrF6]. Adducts NgF(2)center dot CrOF4 and NgF(2)center dot 2CrOF(4)(Ng = Xe, Kr) were synthesized and structurally characterized at low temperatures. The geometry of XeF6 was studied in solid argon and neon matrices. Xenon hexafluoride is a well-known fluoride ion donor forming various [XeF5](+) and [Xe2F11](+) salts. A large number of crystal structures of previously known or new [XeF5](+) and [Xe2F11](+) salts were reported, i.e., [Xe2F11][SbF6], [XeF5][SbF6], [XeF5][Sb2F11], [XeF5][BF4], [XeF5][TiF5], [XeF5](5)[Ti10F45], [XeF5][Ti3F13], [XeF5](2)[MnF6], [XeF5][MnF5], [XeF5](4)[Mn8F36], [Xe2F11](2)[SnF6], [Xe2F11](2)[PbF6], [XeF5](4)[Sn5F24], [XeF5][Xe2F11][(CrOF5)-O-V]center dot 2Cr(VI)OF(4), [XeF5](2)[(CrF6)-F-IV]center dot 2Cr(VI)OF(4), [Xe2F11](2)[(CrF6)-F-IV], [XeF5](2)[(Cr2O2F8)-O-V], [XeF5](2)[(Cr2O2F8)-O-V]center dot 2HF, [XeF5](2)[(Cr2O2F8)-O-V]center dot 2XeOF(4), A[XeF5][SbF6](2)(A = Rb, Cs), Cs[XeF5][BixSb1-xF6](2)(x = -0.37-0.39), NO2XeF5(SbF6)(2), XeF5M(SbF6)(3)(M = Ni, Mg, Zn, Co, Cu, Mn and Pd) and (XeF5)(3)[Hg(HF)](2)(SbF6)(7). Despite its extreme sensitivity, many new XeO3 adducts were synthesized, i.e., the 15-crown adduct of XeO3, adducts of XeO3 with triphenylphosphine oxide, dimethylsulfoxide and pyridine-N-oxide, and adducts between XeO3 and N-bases (pyridine and 4-dimethylaminopyridine). [Hg(KrF2)(8)][AsF6](2)center dot 2HF is a new example of a compound in which KrF2 serves as a ligand. Numerous new charged species of noble gases were reported (ArCH2+, ArOH+, [ArB3O4](+), [ArB3O5](+), [ArB4O6](+), [ArB5O7](+), [B-12(CN)(11)Ne](-)). Molecular ion HeH+ was finally detected in interstellar space. The discoveries of Na2He and ArNi at high pressure were reported. Bonding motifs in noble-gas compounds are briefly commented on in the last paragraph of this review.
