Mononitrosyl- undtrans-Dinitrosyl-Komplexe von Phthalocyaninaten des Mangans und Rheniums

Abstract

Professor Kurt Dehnicke zum 70. Geburtstag gewidmet Inhaltsu È bersicht. Tetra(n-butyl)ammonium-oder Di(triphenylphosphan)iminium nitrosylacidophthalocyaninato(2±)manganat, (cat)[Mn(NO)(X)pc 2± ] (X = ONO, NCO, N 3 ; cat = n Bu 4 N, PNP) wird aus [Mn(X)pc 2± ], (cat)NO 2 und ( n Bu 4 N)BH 4 in CH 2 Cl 2 oder aus Nitrosylphthalocyaninato(2±)mangan, [Mn(NO)pc 2± ] und ( n Bu 4 N)X (X = ONO, NCO, N 3 , NCS) bei T < 120°C dargestellt. [Mn(NO)pc 2± ] fa È llt aus einer Lo È sung von [Mn(NO)(X)pc 2± ] ± in Methanol aus. Aus Nitrito(O)phthalocyaninato(2±)mangan bildet sich mit (cat)NO 2 und Hydrogensulfid als Reduktionsmittel trans-Di(nitrosyl)phthalocyaninato(2±)manganat, trans [Mn-(NO) 2 pc 2± ] ± , das man als rot-violettes (PNP)-und ( n Bu 4 N)-Komplexsalz isoliert. [Mn(NO)(OPPh 3 )pc 2± ] erha Èlt man durch Addition von OPPh 3 an [Mn(NO)pc 2± ] bei 200°C. Di(triphenylphosphan)phthalocyaninato(2±)rhenium(II) bildet mit (PNP)NO 2 in CH 2 Cl 2 oder beim Schmelzen mit (PNP)NO 2 und PPh 3 bei 100°C gru È nblaues l-Di(triphenylphosphan)iminiumnitrosylnitrito(O)phthalocyaninato(2±)rhenat, l (PNP)[Re(NO)(ONO)pc 2± ]. Bei sonst gleichen Bedingungen kristallisieren mit ( n Bu 4 N)NO 2 aus der Schmelze rote, hauchdu È nne Pla È ttchen von Tetra-(n-butyl)ammonium-trans-di(nitrosyl)phthalocyaninato(2±)rhenat, ( n Bu 4 N) trans [Re(NO) 2 pc 2± ]. Aus konzentrierter Lo È sung von ( n Bu 4 N) trans [Re(NO) 2 pc 2± ] in Pyridin fa È llt nach Zugabe von (PNP)Br oder (PNP)PF 6 das entsprechende Komplexsalz l (PNP) trans [Re(NO) 2 pc 2± ] aus. ( n Bu 4 N) trans [Re(NO) 2 pc 2± ] reagiert bei 300°C mit PPh 3 zu blaugru È nem Nitrosyltriphenylphosphanoxidphthalocyaninato(2±)rhenium, [Re(NO)-(OPPh 3 )pc 2± ], welches mit Iod zu Nitrosyltriphenylphosphanoxidphthalocyaninato(2±)rheniumtriiodid, [Re(NO)-(OPPh 3 )pc 2± ]I 3 oxydiert wird. Die Kristallstrukturen von l (6) und [Re(NO)(OPPh 3 )pc 2± ]I 3´C H 2 Cl 2 (7) sind bestimmt worden. Der (M±N(NO))-Abstand variiert zwischen 1,623(12) A Ê in 5 und 1,846(3) A Ê in 3. Das (M±N±O)-Geru È st ist quasi-linear. In den UV-Vis-Spektren, die kaum von der Art des Metallatoms, Axialliganden und Metalloxydationszustands abha È ngen, liegt die B-Bande bei ca. 14500 cm ±1 und die Q-Bande bei 30400 cm ±1 . In den IR-Spektren beobachtet man (N±O)-Valenzschwingungen zwischen 1701 cm ±1 in 3 und 1753 cm ±1 in [Mn(NO)pc 2± ] bzw. 1571 cm ±1 in 4 und 1724 cm ±1 in 7. (M±N(NO))-Valenz-und (M±N±O)-Deformationsschwingungen treten in den IRbzw. Resonanz-Raman-Spektren zwischen 486 cm ±1 in 4 und 620 cm ±1 in 1 auf. Mononitrosyl and trans-Dinitrosyl Complexes of Phthalocyaninates of Manganese and Rhenium Abstract. Tetra(n-butyl)ammonium or di(triphenylphosphane)iminium nitrosylacidophthalocyaninato(2±)manganate, (cat)[Mn(NO)(X)pc 2± ] (X = ONO, NCO, N 3 ; cat = n Bu 4 N, PNP) is prepared from acidophthalocyaninato(2±)manganese, [Mn(X)pc 2± ], (cat)NO 2 and ( n Bu 4 N)BH 4 in CH 2 Cl 2 or from nitrosylphthalocyaninato(2±)manganese, [Mn(NO)pc 2± ] and ( n Bu 4 N)X (X = ONO, NCO, N 3 , NCS) at T < 120°C, respectively...

A Rare Type of Rhenium(I) Diimine Complexes with Unsupported Coordinated Phosphine Oxide Ligands: Synthesis, Structural Characterization, Photophysical and Theoretical Study

“…This interaction also results in deviation of the structure from idealized octahedral geometry to give a noticeable decrease in the O–Re–N angles, which range from 76.41 to 80.38 degrees. The distortions of this type were also observed in closely analogous complexes containing aromatic di‐ and tetra‐imines in cis position with respect to Re–O(–P) bond,, in the latter case the whole tetradentate phthalocyaninato aromatic system being bent to shorten the distance to the oxygen atom of a rather bulky phosphine oxide ligand. These observations indicate the presence of an interaction between the phosphine oxide ligand and the diimine aromatic system that can be assigned to a combination of electrostatic attraction between negatively charged PO oxygen atom and positively charged diimine carbon atoms (see Table S2) together with a possible donor–acceptor interaction of the oxygen loan pair and unoccupied π*‐orbitals of the diimine aromatic system, which stabilize relatively weak bonding of the hard donor ligand to the soft metal center.…”

X-ray structure of [Re(NO)2.09Br1.91(PPh3)2] and DFT studies of [Re(NO)2Br2(PPh3)2]

“…The trans arrangement of the two bulky triphenylphosphine molecules causes the cis location of the nitrosyl groups with respect to PPh 3 (-acid ligands). This is due to the electronic influence of the [41]. In all the other structurally characterised mononuclear dinitrosyl rhenium complexes NO ligands adopt a bent structure [42][43][44][45].…”

Understanding the unexpected linearity of the - Mn(NO) unit in a phthalocyanine complex: some thoughts on dinitrosylheme intermediates in biology

“…However, a number of complexes do not fit this paradigm and feature linear MNO angles, even though n > 6, posing a theoretical challenge. Thus, using density functional theory (DFT, PW91/TZP), we have attempted to understand the relative linearity of the MNO units in a unique trans-{Mn(NO) 2 } 8 complex (see [10,11] for our earlier studies in this area), the Mn(Pc)(NO) 2 ] À (Pc = phthalocyaninato) anion [12]. (All geometry optimizations were carried out using the ADF program system, the VWN ''local'' functional, Perdew-Wang 1991 (PW91) gradient-corrected functionals for both exchange and correlation, Slater-type triple-f plus polarization (TZP) basis sets, and a fine mesh for numerical integration of matrix elements.…”

“…These orbital interactions would not be symmetry-allowed if the axial ligands were present in an upright or transoid orientation. In contrast to the trans{Fe(NO) 2 } 8 porphyrin species, the X-ray crystal structure of an [Mn(Pc)(NO) 2 ] À salt reveals a near-D 4h anion, with a near-linear ON-Mn-NO arrangement [12]. What accounts for the linearity of the {Mn(NO) 2 } 8 group?…”

“…We eventually reached the conclusion that [Mn(Pc)(NO) 2 ] À had to be paramagnetic, most likely S = 1. While the original experimental paper [12] does not address this issue, Prof. Homborg, the senior author of this work, informed us on inquiring that this was indeed the case. With the assumption of an S = 1 state, a D 4h symmetry-constrained geometry optimization of [Mn(Pc)(NO) 2 ] À converged smoothly to yield a final geometry that agreed well with experiment [12].…”