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This study describes the synthesis of 12 new germanium complexes containing β-diketonate and/or N -alkoxy carboxamidate-type ligands as precursors for GeO 2 through atomic layer deposition (ALD). A series of Ge(β-diketonate)Cl complexes such as Ge(acac)Cl ( 1 ) and Ge(tmhd)Cl ( 2 ) were synthesized by using acetylacetone (acacH) and 2,2,6,6-tetramethyl-3,5-heptanedione (tmhdH). N -Alkoxy carboxamidate-type ligands such as N -methoxypropanamide (mpaH), N -methoxy-2,2-dimethylpropanamide (mdpaH), N -ethoxy-2-methylpropanamide (empaH), N -ethoxy-2,2-dimethylpropanamide (edpaH), and N -methoxybenzamide (mbaH) were used to afford further substituted complexes Ge(acac)(mpa) ( 3 ), Ge(acac)(mdpa) ( 4 ), Ge(acac)(empa) ( 5 ), Ge(acac)(edpa) ( 6 ), Ge(acac)(mba) ( 7 ), Ge(tmhd)(mpa) ( 8 ), Ge(tmhd)(mdpa) ( 9 ), Ge(tmhd)(empa) ( 10 ), Ge(tmhd)(edpa) ( 11 ), and Ge(tmhd)(mba) ( 12 ), respectively. Thermogravimetric analysis curves, which mostly exhibited single-step weight losses, were used to determine the evaporation properties of complexes 1 - 12 . Interestingly, liquid complex 2 has no residue at 198 °C and therefore exhibits excellent vaporization properties and high volatility. Single-crystal X-ray diffraction studies of 1 and 7 demonstrated that the complexes had monomeric molecular structures with germanium chelated by the oxygen atoms of one or two bidentate ligands, respectively. An ALD process was developed for the growth of GeO 2 using Ge(tmhd)Cl ( 2 ) as a new precursor and H 2 O 2 as an oxidant. This study demonstrates the achievement of self-limiting growth of GeO 2 films by varying the duration of injection/purge, with an observed ALD window at deposition temperatures ranging from 300 to 350 °C. The saturated growth per cycle of the GeO 2 film was determined as 0.27 Å/cycle at a deposition temperature of 300 °C. The deposited films were observed to be amorphous consisting of GeO 2 ., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

A new heteroleptic complex series of tin was synthesized by the salt metathesis reaction of SnX 2 (X = Cl, Br, and I) with aminoalkoxide and various N -alkoxy-functionalized carboxamide ligands. The complexes, [ClSn(dmamp)] 2 ( 1 ), [BrSn(dmamp)] 2 ( 2 ), and [ISn(dmamp)] 2 ( 3 ), were prepared from the salt metathesis reaction of SnX 2 with one equivalent of dmamp; [Sn(dmamp)(empa)] 2 ( 4 ), [Sn(dmamp)(mdpa)] 2 ( 5 ), and [Sn(dmamp)(edpa)] 2 ( 6 ) were prepared via the salt metathesis reaction using complex 2 with one equivalent of N -alkoxy-functionalized carboxamide ligand. Complexes 1 - 5 displayed dimeric molecular structures with tin metal centers interconnected by μ 2 -O bonding via the alkoxy oxygen atom. The molecular structures of complexes 1 - 5 showed distorted trigonal bipyramidal geometries with lone pair electrons in the equatorial position. Using complex 6 as a tin precursor, SnO x films were deposited by chemical solution deposition (CSD) and subsequent post-deposition annealing (PDA) at high temperatures. SnO and SnO 2 films were selectively obtained under controlled PDA atmospheres of argon and oxygen, respectively. The SnO films featured a tetragonal romarchite structure with high crystallinity and a preferred growth orientation along the (101) plane. They also exhibited a lower transmittance of >52% at 400 nm due to an optical band gap of 2.9 eV. In contrast, the SnO 2 films exhibited a tetragonal cassiterite crystal structure and an extremely high transmittance of >97% at 400 nm was observed with an optical band gap of 3.6 eV., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)