Dialkylcarbamato magnesium cluster complexes: precursors to the single-source chemical vapour deposition of high quality MgO thin films

Recent Advances in the Chemistry of Metal Carbamates

“…The thermal degradation of homoleptic carbamates or oxido-carbamates under inert atmosphere usually proceeds quantitatively at temperatures below 500 °C with fragmentation of the organic groups, cleanly affording a metal oxide. The fate of the carbamato ligands during the pyrolytic process depends on the system; in general, multiple products have been detected in the gas phase, including CO 2 and the dialkylamine [ 42 , 240 , 333 , 334 ] ( Scheme 41 a). In some cases, the preferential formation of alkyl isocyanates and alkenes has been recognized ( Scheme 41 b–d) [ 335 , 336 ].…”

Magnesium β-ketoiminates as CVD precursors for MgO formation

“… 43–46 However, the crystallinity of MgO layers depends not only on the substrate temperature but also on the oxygen flow, 47 which can change by using diverse precursors. 48–50 …”

“…Over the last few years, various organometallic and metal–organic compounds have been used as MgO CVD precursors, including [Mg( η 5 -C 5 H 4 R) 2 ] (R = H, 20 R = Me ( ref. 21 )), [Mg(β-diketonate) 2 ] (β-diketonate = acac, 22 thd 22,23 ), [Mg(β-diketonate) 2 (tmeda)] (β-diketonate = thd, 3,24 = hfac 1 ), [Mg(O 2 CR) 2 ] (R = C 7 H 15 , CNEt 2 ), 25 [Mg 4 Me 4 (O t Bu) 4 ], 26 [Mg 6 (O 2 CNEt 2 ) 12 ], 27 [Mg(DMADB) 2 ] 6 , and [bis[5- N -( N , N -dimethylaminopropyl)-2,2,7-trimethyl-3-octanonato] magnesium] 28 (acac = acetylacetonate, thd = 2,2,6,6-tetramethyl-3,5-heptanedionate, hfac = 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate, tmeda = N , N , N ′, N ′-tetramethylethylenediamine, DMADB = N , N -dimethylaminodiboranate). Among them, the magnesium β-diketonates are very promising CVD precursors, due to their ability to fulfill the requirements needed for gas-phase deposition experiments, which are, for example, high stability and cost-effective and straightforward high yield synthetic methodologies.…”

Synthesis and Isomerisation Reactions of Tetranuclear and Octanuclear (Carbamato)zinc Complexes

“…[27] Heterodimetallic carbamato complexes are attractive from a metal oxide film growth perspective. The homonuclear complex [Mg 6 (O 2 CNEt 2 ) 12 ] is already a proven precursor for MgO thin-film growth, [28] and when mixed with the (µ-oxido)zinc analogue [Zn 4 (µ 4 -O)(O 2 CNEt 2 ) 6 ] has been used to deposit dimetallic Zn x Mg 2-x O films of high quality and reproducibility. [29] The next logical step is thus the "mixing" of dimetallic systems at the molecular level, through the formation of a heteronuclear (carbamato)zinc/ magnesium complex.…”