New Dimethyl(norbornadienyl)platinum(II) Precursors for Platinum MOCVD

Abstract

The synthesis, characterization, and application as CVD precursors of several new dimethyl(norbornadienyl)platinum(II) compounds are reported. Initially, synthesis is performed in a two-step procedure from K 2 PtCl 4 with (Rnbd)PtI 2 as an intermediate, but a convenient "one-pot" procedure is developed that allows the formation of platinum(II) precursors with good yield and purity. Novel platinum compounds are; (nbd)PtMe 2 (1), (7-Me-nbd)PtMe 2 (2), (7-Et-nbd)PtMe 2 (3), (7-i Pr-nbd) PtMe 2 (4), and (2-Et-nbd)PtMe 2 (5). Compounds 1 À 4 are solids while 5 is liquid at room temperature. Fine-tuning of the organic environment provides some control of the thermal stability and volatility. Liquid-delivery CVD is reported using 1 and 5 Pt precursor solutions. Excellent results are obtained in the presence of oxygen as a co-reactant. The as-deposited Pt films are analyzed in terms of morphology, crystalline structure, and composition.

Platinum ω-Alkenyl Compounds as Chemical Vapor Deposition Precursors: Synthesis and Characterization of Pt[CH2CMe2CH2CH═CH2]2 and the Impact of Ligand Design on the Deposition Process

“…We describe all of the 1 J PtC coupling constants to the olefin groups in 2 – 4 as “small” because in other platinum­(II) cis -dialkyl diolefin complexes they are usually much larger: 55 Hz in (COD)­PtMe 2 , 46 Hz in the norbornadiene compound (NBD)­PtMe 2 , and 44.6 Hz in the neopentyl compound (COD)­Pt­(CH 2 CMe 3 ) 2 . Interestingly, the 1 J PtC coupling constants to the olefinic carbons in 3 are also smaller than those of 50 and 40 Hz in the unmethylated analog Pt­[(CH 2 ) 3 CHCH 2 ] 2 , 1 . This latter comparison suggests that the 2,2-dimethyl substitution in complexes 2 – 4 weakens the Pt–olefin bonding, perhaps by a combination of electronic factors (the trans influence of the neo-alkyl groups is larger than that of n -alkyl groups) and steric factors (the 2-methyl groups force the rings to adopt conformations that are less favorable for Pt–olefin overlap).…”

“…75 Interestingly, the 1 J PtC coupling constants to the olefinic carbons in 3 are also smaller than those of 50 and 40 Hz in the unmethylated analog Pt[(CH 2 ) 3 CHCH 2 ] 2 , 1. 76 This latter comparison suggests that the 2,2-dimethyl substitution in complexes 2−4 weakens the Pt−olefin bonding, perhaps by a combination of electronic factors (the trans influence of the neo-alkyl groups is larger than that of n-alkyl groups) 77 and steric factors (the 2-methyl groups force the rings to adopt conformations that are less favorable for Pt−olefin overlap).…”

Volatile Iridium and Platinum MOCVD Precursors: Chemistry, Thermal Properties, Materials and Prospects for Their Application in Medicine

“…• alkylplatinum derivatives with monodentate ligands: Me(R)PtQ 2, where R = Me, CO, HC = CH 2 , t BuC≡C, ï 3 -C 3 H 5 ; Q = HCN, R'CN [74,75]; • dimethylplatinum derivatives with bidentate ligands: Me 2 Pt(Q), where Q = tmeda (N,N,N ,N -tetramethylethylenediamine) [15], hd and its derivatives [77], nbd and its derivatives [78], cod and its derivatives [79,80] [81,82] (Table 1).…”

Chemical vapour deposition of platinum films on electrodes for pacemakers: Novel precursors and their thermal properties

“…Suitable MOCVD precursors are required to be volatile, thermally stable at vaporization, nontoxic, stable in air and easy to prepare in high yields . Pt forms volatile compounds with methyl, allyl, cyclopentadienyl (Cp) and β‐diketonato ligands . These types of Pt precursors were usually used for a definite purpose.…”

“…These types of Pt precursors were usually used for a definite purpose. For example, dimethylplatinum(II) compounds have been used for Pt nanoparticle deposition for catalysts . Trimethylplatinum(IV) compounds with Cp or its derivatives were widely used for deposition of Pt films with compact structure and low roughness for microelectronic and protective coating applications .…”