Chemistry of a cofacial dirhodium diporphyrin: Synthesis and reactivity of Rh[sub 2]DPB

Journal Article · Wed Apr 28 04:00:00 EDT 1993 · Inorganic Chemistry; (United States)

DOI:https://doi.org/10.1021/ic00061a040· OSTI ID:6260095

Collman, J P; Ha, Yunkyoung; Guilard, R; Lopez, M A ^[1]

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1. Stanford Univ., CA (United States)

A novel cofacial dirhodium diporphyrin with a metal-metal single bond has been synthesized in two steps from the corresponding free base cofacial porphyrin H[sub 4]DPB. Rhodium insertion and subsequent photolysis yield the cofacial dirhodium diporphyrin Rh[sub 2]DPB. This cofacial dirhodium diporphyrin activates H[sub 2] with the assistance of ancillary ligands which attack the rhodium centers externally, weakening the metal-metal bond. The reaction of the dirhodium diporphyrin with H[sub 2] and CO yields the dirhodium diporphyrin dihydride Rh(H)Rh(H)DPB. The H[sub 2] cleavage reaction seems to occur within the cavity of the cofacial diporphyrin, on the basis of the unusually high T[sub 1] values of the resultant hydrides and the predicted regiospecific bonding pattern of additional, bulky ancillary ligands. This reactivity differs from that of a monomeric rhodium porphyrin system which gives a formyl complex. Phosphines have also been employed in reaction with the dirhodium diporphyrin and H[sub 2], resulting in a different type of hydride complex, seemingly one having three-center two-electron bonds. 25 refs., 8 figs., 1 tab.

• OSTI ID: 6260095
• Journal Information: Inorganic Chemistry; (United States), Journal Name: Inorganic Chemistry; (United States) Vol. 32:9; ISSN 0020-1669; ISSN INOCAJ
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBOXYLIC ACIDS
CHALCOGENIDES
CHEMICAL ACTIVATION
CHEMICAL PREPARATION
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
COMPLEXES
DECOMPOSITION
ELEMENTS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDRIDES
HYDROGEN
HYDROGEN COMPOUNDS
LIGANDS
NONMETALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOSPHINES
PHOSPHORUS COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PORPHYRINS
REACTIVITY
REFRACTORY METAL COMPOUNDS
RHODIUM COMPLEXES
RHODIUM COMPOUNDS
RHODIUM HYDRIDES
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
TRANSITION ELEMENT COMPOUNDS
YIELDS