VOL'PIN and SHUR have recently explored the and PF,-. These salts are the first reported possibility of fixing molecular nitrogen under mild compounds in which N, is co-ordinated t o a c0nditions.l-3 We now report that from aqueous transition metal. The iodide salt is diamagnetic solutions of ruthenium trichloride (free from nitric and has the following analysis: N, 20.52; H, 3.96; oxide) and hydrazine hydrate a t 25" it is possible NH,, 17.84; I, 54.05%.

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The infrared spectra of the complexes [ R u bands. The metal-nitrogen stretching vibrations were observed between 485-424 cm-I for the ruthenium(II1) complexes but were not observed for the ruthenium(I1) complexes in this region.Canadian Journal of Chemistry. Volume 45, 1337 (1967 Nakamoto has reviewed the infrared spectra of ammine complexes of transition metals (I). Recently, a number of workers have studied the spectra of ammine complexes in the far infrared (below 300 cm-I) (2-5). I n this paper we report the preparation and the infrared spectra of a number of hexammine and pentammine complexes of ruthenium (I I) and ruthenium (I I I). RESULTS AWD DISCUSSION( a ) C&nplexes [Ru(NH3)6]X2 and lRu(NH3J~lx3 The infrared data for these complexes are presented i n Table I , together with the assignments for the observed absorption bands.Band assignments between 4 000 -650 cm-l were made in the usual manner (3). T h e N-deuterated complex, [ R L I ( N D~)~] C I~, was prepared to facilitate the assignment of the NH3 bands. The data for this particular complex are presented in Table 11. I t may be noted that the NH stretching vibrations for the halide salts were not readily resolved. This may be attributed to hydrogen bonding between the ammonia hydrogen atoms and the counter ion. Replacing a halide anion by a complex anion such as fluoroborate renders the NH stretching vibrations readily resolvable. For both the ruthenium-(I I) and ruthenium (I I I) fluoroborate salts, two very strong bands were observed which may be assigned to NH stretching vibra- tions. The NH stretching vibrations occurred a t a higher frequency for the ruthenium-(11) complexes. This is consistent with the idea that the greater the charge on the metal, the stronger the M-N bond and hence a weakening of the NH bond with a corresponding decrease in frequency for the NH stretching vibrations.The NH3 rocking vibration for these complexes is quite sensitive t o a change in oxidation state of the central metal ion. For this vibration, the higher oxidation state exhibits a higher NH3 rocking vibrational frequency. This is in agreement with the spectra of the analogous hexammine complexes of cobalt (11) and cobalt (111) ( 2 , 3).

Bands have been assigned to stretching frequencies of bonds between platinumand chlorine, nitrogen and oxygen which are observed in the far infrared region. The positions of these bands have been related to the structures of several complexes. Iiuproved procedures are given for the preparation of complexes of the type I< [P~CIJL] and trans-PtCI?L(arn), where L is an unsaturated organic ligand and a m is an aromatic amine.As part of a study of the trans effect of unsaturated organic ligands in chloro-complexes of bivalent platinum, the infrared spectra of a series of such conlpounds have been examined in the 300-800 cin-I region. Variations in the stretching frequencies, v Pt-C1, have been investigated and assignments made for the platinum -aromatic nitrogen stretching modes, v Pt-N. From the spectrum of bis(acety1acetono) platinum(I1) stretching frequencies v Pt-0 have been determined. RESULTS AND DISCUSSION (a) Chloro-complexesIn Table I where L is an unsaturated organic ligand. Since the coinplex ion is essentially square planar, with the platinuin atom a t the center, we expect to find two platinum-chlorine stretching frequencies: (a) the asyinmetric stretching vibration of the linear C1-Pt-C1 unit (the syinilletric vibration being inactive in the infrared); and (b) the stretching frequency of the platinum-chlorine group trans to the ligand L. This latter frequency should be lower than the first because of the weakening of the bond by the high trans effect of the unsaturated ligand (1) as reported by Adams and Chatt (2) for the propene platinous chloride ion. We find that the stretching frequency of the trans chlorine (306-314 cnl-I) is some 20 cm-I lower than that of the Cl-Pt-C1 unit (325-340 cin-I), which is in accordance with expectations. For the ally1 alcohol complex the band a t 305 cm-I is rather weak and may be affectedIPresent address:

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