New s‐Block Metal Pyridinedicarboxylate Network Structures through Gas‐Phase Thin‐Film Synthesis

Abstract

The combined atomic and molecular layer deposition (ALD/MLD) technique offers a unique way to build—both known and previously unknown—crystalline coordination polymer materials directly from gaseous precursors in a high‐quality thin‐film form. Here, we demonstrate the ALD/MLD of crystalline Li‐, Na‐, and K‐based 3,5‐pyridinedicarboxylate (3,5‐PDC) thin films; the Li2‐3,5‐PDC films are of the known Li‐ULMOF‐4 crystal structure whereas the other as‐deposited crystalline films possess structures not previously reported. Another exciting possibility offered by ALD/MLD is the deposition of well‐defined but amorphous metal–organic thin films, such as our Mg‐, Ca‐, Sr‐, and Ba‐based 3,5‐PDC films, which can then be crystallized into water‐containing structures through a post‐deposition humidity treatment. All together, the new metal–organic structures realized in this study through ALD/MLD comprise a majority of the (anhydrous and water‐containing) members of the s‐block metal 3,5‐pyridinedicarboxylate family.

Atomic/molecular layer deposition and electrochemical performance of dilithium 2-aminoterephthalate

“…2b); this is a trend seen for most of the reported ALD/MLD processes. 8,14,15,17,18,25,26 We also confirmed the linearity of the film growth with an increasing number of ALD/MLD cycles after a small incubation period in the beginning (Fig. 2c).…”

“…12 The recent developments in the field of ALD/MLD have opened new avenues towards new interesting metal-organic materials. 8,[13][14][15][16][17][18] Here we extend the ALD/MLD material repertoire to dilithium 2-aminoterephthalate (Li 2 TP-NH 2 ), which then allows us to evaluate the role of the electron-donating amino group on the redox potential of the terephthalate skeleton, with the anticipation that the somewhat high redox potential of Li 2 TP could be decreased by introducing the additional amino group (Fig. 1).…”

Electrochemically Active In Situ Crystalline Lithium-Organic Thin Films by ALD/MLD

“…These values are in line with those previously observed for Li-TPA and Li-PDC. 24 , 29 , 33 , 37 Next, we investigated the growth rate at different temperatures ( Figure 3 a), to find out that the GPC decreases with increasing deposition temperature, which is a common but poorly understood feature in ALD/MLD. 33 , 44 , 45 The organics employed have very low vapor pressures in addition to their bifunctionality, which makes them sticky, possibly causing some molecules to stick on the film and act as an extra surface site especially in the lower temperature regime.…”

“…Most importantly, the distance (Δ) between the two carboxylate absorption bands ( Figure 6 ) provides us strong support toward the bidentate bridging-type bonding mode in our Li-dicarboxylate thin films, which is expected for 130 cm –1 < Δ < 200 cm –1 . 48 , 49 Note that the FTIR spectrum for Li-PDC was discussed in detail in our previous work 37 and thus left out from the present discussion. Nevertheless, it should be mentioned that the spectrum confirmed the participation of the pyridyl-N entity in the metal coordination.…”

Atomic layer deposition of thermoelectric layered cobalt oxides

“…Sodium has been a kind of white spot among the elements used in ALD processes, except in the pioneering works exploring sodium tert-butoxide, sodium hexamethyldisilazide, and sodium trimethylsilanolate precursors of limited stability for the ALD of sodium aluminates, silicates, niobates, and tantalates; 25,26 the ALD of Na oxide was not challenged due to its hygroscopic nature. Our group then challenged combined ALD and molecular layer deposition processes for Na-containing inorganic-organic hybrid thin films using Na-2,2,6,6-tetramethyl-3,5-heptanedionate as the precursor for sodium; [27][28][29] thermal stability of that precursor enabled reproducible depositions at temperatures as high as 300°C. The ALD of cobalt oxides is still an active matter of research as can be seen from the list in Table I.…”