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The graphical abstract illustrates antiwear efficiency of studied low SAPS Schiff bases and their copper(ii) complexes.

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Guest-promoted modulation of the electronic states in metal−organic frameworks (MOFs) has brought about a new field of interdisciplinary research, including host−guest chemistry and solid-state physics. Although there are dozens of studies on guestpromoted enhancement of the electrical conductivity properties, including stoichiometry, conductive carriers and structure−property relationships have been scarcely studied in detail. Herein, we studied the effects of continuous and controlled bromine vapor doping on structural, optical, thermoelectric, and semiconducting properties of Cu[Cu(pdt) 2 ] (pdt = 2,3-pyrazinedithiolate) as a function of bromine stoichiometry. We demonstrated that the same material could act as both p-and n-type semiconductors by tuning the stoichiometry of Br doped in Br x @Cu[Cu(pdt) 2 ], and a change in the charge-carrier type from holes in pristine MOF to electrons upon bromine vapor doping was observed. Bromine molecules acted as an oxidant, causing the selective oxidation of [Cu II (pdt) 2 ] in the host framework. In addition, a redox hopping pathway between the partially oxidized Cu II /Cu III center contributed to the enhancement of the electrical conductivity of the MOF.

The combination of single-ion magnets (SIMs) and metal-organic frameworks (MOFs) is expected to produce new quantum materials. The principal issue to be solved in this regard is the development of new strategies for the synthesis of SIM-MOFs. This work demonstrates a new simple strategy for the synthesis of SIM-MOFs where a diamagnetic MOF is used as the framework into which the SIM sites are doped. 1 mol%, 0.5 mol%, and 0.2 mol% of the Co(II) ions are doped into the Zn(II) sites of [CH6N3][ZnII(HCOO)3]. The doped Co(II) sites in the MOFs perform as SIM with a positive D term of zero-field splitting. Temperature dependency of the relaxation time suggests suppressing spin- lattice relaxation by the rigid framework. Thus, this work represents a proof of concept for the creation of single-ion doped magnets in MOFs. This simple synthetic strategy will be widely applied for the creation of quantum magnetic materials.

The combination of single‐ion magnets (SIMs) and metal–organic frameworks (MOFs) is expected to produce new quantum materials. The principal issue to be solved in this regard is the development of new strategies for the synthesis of SIM‐MOFs. This work demonstrates a new simple strategy for the synthesis of SIM‐MOFs where a diamagnetic MOF is used as the framework into which the SIM sites are doped. 1, 0.5, and 0.2 mol% of the Co(II) ions are doped into the Zn(II) sites of [CH6N3][ZnII(HCOO)3]. The doped Co(II) sites in the MOFs perform as SIM with a positive D term of zero‐field splitting. The longest magnetic relaxation time is 150 ms (0.2 mol% Co) at 1.8 K under a static field of 0.1 T. Temperature dependency of the relaxation time suggests suppressing magnetic relaxation by reduction of spin–spin interaction upon doping in the rigid framework. Thus, this work represents a proof of concept for the creation of a single‐ion doped magnet in the MOF. This simple synthetic strategy will be widely applied for the creation of quantum magnetic materials.

New three-dimensional (3D) lanthanide framework compounds supported by bridging thiocyanate ligand and K+ cations, K4[Ln(NCS)4(H2O)4](NCS)3(H2O)2(1: Ln = Dy, 2: Ln = Tb, 3: Ln = Gd) have been synthesized. A single-crystal X-ray diffraction study showed that all three compounds were isostructural and crystallized in the I 2/a space group. The K+ ion form 2D layers with thiocyanates which are further linked by [Ln(NCS)4(H2O)4]- complexes and additional thiocyanate ions to generate an interesting 3D framework structure. Compound 1 shows slow magnetic relaxation behavior under a zero direct current (DC) field, indicating that 1 behaves as a single-ion magnet (SIM). As estimated from AC magnetic measurements, the effective energy barrier for spin reversal in 1 was Ueff = 42 cm–1. Slow relaxation of magnetization under a small external DC field was also detected for 2 and 3 at 1.8 K.