electronic reprint
Acta Crystallographica Section C

Crystal Structure
Communications
ISSN 0108-2701

Editor: George Ferguson

Pt2II and Pt2 III dimers containing aPt2(2,2 -bipyridine)2 ( -N,N-dimethylguanidinato)2 unit¼

Ken Sakai, Kazuo Yokokawa and Yoshimi Yokoyama

Copyright © International Union of Crystallography
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Acta Cryst. (2007). C63, m36–m41(C3 H10 N3 )[Pt2 (C3 H8 N3 )2 (SO4 )2 (C10 H8 N2 )2 ]NO3 6H2 O

Sakai et al. ¯ [Pt2 (C3 H8 N3 )2 (C10 H8 N2 )2 ](PF6 )2 2CH3 CN and &  
ibility in their PtÐPt distances upon formation of this bond as
the partial oxidation at the metal centres proceeds (Sakai,
Tanaka et al., 1998). As an extension of studies of such   !     ! 
94 !"6    0   lNN 
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The syntheses and crystal structures of the title PtII
2 and Pt2
dimers doubly bridged with N,N-dimethylguanidinate ligands,
namely bis(-N,N-dimethylguanidinato)bis[(2,20 -bipyridine)platinum(II)](PtÐPt) bis(hexa¯uorophosphate) acetonitrile
disolvate, [PtII
2 (C3H8N3)2(C10H8N2)2](PF6)22CH3CN, (I), andguanidinium bis(-N,N-dimethylguanidinato)bis[(2,20 -bipyridine)sulfatoplatinum(III)](PtÐPt) bis(hexa¯uorophosphate)nitrate hexahydrate, (C3H10N3)[PtIII2(C3H8N3)2(SO4)2(C10H8N2)2]NO36H2O, (II), are reported. The oxidation of the PtII
2
dimer into the PtIII
2 dimer results in a marked shortening of theÊ . The change isPtÐPt distance from 2.8512 (6) to 2.5656 (4) A
mainly compensated for by the change in the dihedral angle
between the two Pt coordination planes upon oxidation, from
21.9 (2) to 16.9 (3) . We attribute the relatively strong onedimensional stack of dimers achieved in the PtII
2 compound inpart to the strong PtII  C(bpy) associations (bpy is 2,20 bipyridine) in the crystal structure [Pt  C = 3.416 (10) andÊ ].
3.361 (12) A!One-dimensional materials have attracted considerable
attention due to their highly anisotropic physical properties. In
order to develop new types of one-dimensional substances,interest has for many years concentrated on the use ofdinuclear entities as the repeating units, since the electronic
structures at the metal centres may be controlled prior to theformation of a one-dimensional stack of dimers. In thiscontext, we reported previously that cis-diammineplatinum
dimers doubly bridged with carboxylate ligands afford a newseries of one-dimensional platinum chain compounds with thegeneral formula [Pt2(NH3)4(-carboxylato)2]nm+, where thecharge m depends on the average Pt oxidation state (Sakai,
Takeshita et al., 1998; Sakai et al., 2002). One of the attractive
features of these dimeric units is that they are doubly bridged
by carboxylate ligands in a cis fashion, leading to high ¯ex-"#carboxylate systems, we have also developed a new onedimensional platinum family by combining a cationic diplatinum complex with an anionic mononuclear complex, e.g.
2+and [PtII(oxalato)2]2 (bpy is[PtII
2 (bpy)2(-pivalamidato)2]0
2,2 -bipyridine; Akiyama et al., 2000). In that study, a very
intriguing alternating stack of dimers and monomers wasfound in the crystal structure. It was also found that the socalled `HT±HH' isomerization of the pivalamidate-bridged
dimer took place to give a mixture of two isomers, where HT
and HH correspond to the head-to-tail and head-to-headarrangements, respectively, of the bridging amidate ligands.
The co-existence of these two isomers caused dif®culties in
evaluating the crystal structures and their oligomerization
behaviours in aqueous media. For instance, even if a pure HT
dimer, e.g. HT-[PtII
2 (bpy)2(-pivalamidato)2](NO3)25H2O, isemployed as the starting material, in aqueous media the dimer
gradually undergoes HT±HH isomerization over a day to givea mixture of two isomers (Sakai, 1996). In order to avoid suchcomplications, dimers bridged by guanidinate derivatives,# "6 9   

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The structure of (I), showing the atom-labelling scheme. Displacement
ellipsoids are drawn at the 50% probability level. H atoms have been
omitted for clarity.

59* /6;!"6#(electronic reprint

Acta Cryst. <"6=/ #" (>?

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Views showing three different stacking interactions within the one-dimensional column in (I). (a) The interdimer association of the Pt1  Pt1i geometry.
(b) The intradimer association (labels are only given for the atoms used to estimate the intradimer bpy-to-bpy separation). (c) The interdimer associationof the Pt2  Pt2ii geometry. H atoms have been omitted for clarity. [Symmetry codes: (i) x, y, 1 z; (ii) x, y, z.]

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A side view, showing the way in which three adjacent dimer cations stack
to give a one-dimensional chain in (I). Each dimer±dimer interaction iscorrelated with an inversion centre. H atoms have been omitted forclarity. [Symmetry codes: (i) x, y, 1 z; (ii) x, y, z.]2+e.g. [PtII(bridge is guanidinate, N,N-di2 (bpy)2(-bridge)2]
methylguanidinate, N,N-diethylguanidinate, etc.), have been
examined in our recent studies, since these dimers afford only
one isomer (bridging amidates coordinate with N- and O-atom
donors, while bridging guanidinates coordinate with two
chemically equivalent N-atom donors). We report here theIIIsyntheses and crystal structures of the PtII
2 and Pt2 dimers
bridged by N,N-dimethylguanidinate (dmg) ligands, viz.
III
[PtII
2 (bpy)2(-dmg)2](PF6)22CH3CN, (I), and [Pt2 (bpy)2(SO4)2(-dmg)2](dmgH2)(NO3)6H2O, (II).
The asymmetric unit of (I) consists of a dinuclear platinum(II) cation (Fig. 1), two PF6 anions and two acetonitrile
solvent molecules. The two square-planar PtII coordination
planes are doubly bridged by the N,N-dimethylguanidinate
ligands in a cis fashion. The dihedral angle between the twocoordination planes () is 21.9 (2) , where each coordination

Acta Cryst. <"6=/ #" (>?

plane is de®ned by four coordinated N atoms. In the meanÊ for N1/
plane calculations, the r.m.s. deviations are 0.033 (9) AÊ for N2/N5/N9/N10. The average
N4/N7/N8 and 0.013 (3) A
torsional twist of these coordination planes about the Pt  Pt
vector (!) is 22.5 (10) . Atoms Pt1 and Pt2 are displaced outof their respective least-squares mean planes by 0.038 (5) andÊ , suggesting that they have a mutually repulsive
0.036 (5) Ainteraction. Alternatively, it may be considered that the twoN(bpy) atoms in each Pt coordination plane are shifted out of
the coordination plane due to the attractive ± interaction
within the dimeric unit. Very similar structural features werepreviously observed for [PtII
2 (phen)2(-pivalamidato)2](NO3)22H2O (phen is 1,10-phenanthroline) [hereinafter (III); = 21.5 (4) and ! = 13 (3) ; Sakai et al., 2003]. The two
pyridyl rings attached to atom Pt1 are twisted about thecentral C11ÐC12 bond: N7ÐC11ÐC12ÐN8 = 5.4 (13) andC10ÐC11ÐC12ÐC13 = 3.4 (19) . These two pyridyl planes
are canted at an angle of 5.4 (3) . In contrast, the bpy ligand
bound to atom Pt2 possesses a planar geometry, with a 12Ê.
atom r.m.s. deviation of 0.02 (2) A
The two bpy ligands within the dimeric unit form a stacking interaction. The intradimer bpy-to-bpy separation,de®ned as the separation between the N7/N8/C7/C8/C11/C12
Ê (Fig. 2b).
and N9/N10/C20/C21/C22/C26 planes, is 3.45 (15) A
Ê ] is comparable
The intradimer Pt  Pt distance [2.8512 (6) AÊ reported for (III). The interwith the value of 2.8489 (17) AÊ and Pt2  dimer Pt  Pt distances [Pt1  Pt1i = 4.9369 (9) AiiÊPt2 = 4.5660 (9) A; symmetry codes: (i) x, y, 1 z; (ii) x,y, z] reveal that there is no signi®cant intermolecular
metal±metal interaction in the crystal structure (Fig. 3).
Nevertheless, as previously observed for (III), the dimer units
stack along the c axis in a one-dimensional fashion based onrelatively strong (bpy)±(bpy) and d(Pt)±(bpy) interÊ , Pt1  C10i = 3.470 (13) AÊactions [Pt1  C11i = 3.416 (10) Aii
Êand Pt2  C21 = 3.361 (12) A], which is obviously relevant to
the dark-red colour of the material (see also Figs. 2a, 2c and 4).

 et al.  @B"< (!4(="< !4"="D<B=" % < (4(=@B"< (!4(="<5?="< !4"="D45(electronic reprint"&  

The interplanar separation for the Pt1  Pt1( x, y, 1 z)
Ê , while the corresponding value forstack is 3.31 (4) A
Ê . These values refer to thePt2  Pt2( x, y, z) is 3.34 (1) A
stacking of two crystallographically equivalent planes, relatedby an inversion centre in each case, the planes being Pt1/N7/
N8/C7/C8/C10/C11/C12 and Pt2/N9/N10/C17/C18/C21/C22/
C26, respectively.
The asymmetric unit of (II) consists of a neutral PtIII
2 dimer(Fig. 5), a guanidinium cation, a nitrate anion, and six solvent
water molecules. The axial sites of the dinuclear platinum(III)unit are occupied by sulfate O atoms. An interesting structuralfeature is that each sulfate anion is doubly hydrogen bonded
to the NÐH(dmg) groups (Table 4). The non-coordinatedguanidinium cation is also hydrogen bonded to one of theÊ andcoordinated sulfate anions [N11  O4 = 2.973 (11) AÊN12  O2 = 2.962 (10) A; Table 4]. The bridged Pt  Pt
Ê ] is very close to the value of
distance [2.5656 (4) AÊ reported for the pivalamidate-bridged analogue
2.5664 (6) A[PtIII
2 (bpy)2(-pivalamidato)2(SO4)2]4H2O [hereinafter (IV);
Yokokawa & Sakai, 2004]. This is the second example of acrystal structure of a platinum(III) dimer with the general(bridge is amidate,formula [PtIII
2 (bpy)2(-bridge)2L2]
carboxylate, guanidinate, etc.; L is an axial ligand such as OH2,

Cl , SO42 or NO3 ). The PtIIIÐO(sulfate) distances
Ê ] are also similar to the value of[2.152 (5) and 2.139 (5) AÊ
2.144 (7) A reported for (IV). In this paper, an equatorial
coordination plane within an overall octahedral geometry isde®ned for each PtIII ion as the plane which is perpendicular
to the PtIII  PtIII axis. Thus, one equatorial PtIII coordination
plane is de®ned by N1/N4/N7/N8 and the other by N2/N5/N9/
N10, with a dihedral angle between them of 16.9 (3) and amean torsional twist of 18 (1) . These indicate that theÊ in the Pt  Pt distance upon oxidation
shortening of ca 0.29 Aof (I) to (II) is mainly compensated for by the change in ,
giving only a small change in !. The mean-plane calculations
performed for the four-coordinated equatorial donor atoms

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Crystal packing views, showing one-dimensional columns consisting of
dimer units (a) along the b axis and (b) along the c axis. For clarity, only
one of the two disordered sites (site A) is plotted for each PF6 anion. H
atoms have been omitted for clarity.

"'(

Views of (II), showing (a) a side view and (b) a top view down the
Pt1  Pt2 vector, together with the atom-labelling scheme. For (b), only
those atoms involved in signi®cant intramolecular ± associations arelabelled. Displacement ellipsoids are drawn at the 50% probability level.
H atoms have been omitted for clarity.

 et al.  @B"< (!4(="< !4"="D<B=" % < (4(=@B"< (!4(="<5?="< !4"="D45(electronic reprint

Acta Cryst. <"6=/ #" (>?

 reveal both planes to be planar, with r.m.s. deviations ofÊ for N1/N4/N7/N8 and 0.007 (2) AÊ for N2/N5/N9/0.0004 (2) A
N10. Atoms Pt1 and Pt2 are displaced towards each other outof the local equatorial coordination plane by 0.016 (3) andÊ , respectively.
0.027 (3) A
As shown in Fig. 5(b) and Table 3, the two bpy planes show
short stacking interactions due to the formation of a PtIIIÐ
PtIII single bond. The net separation between the stacked bpy
Ê , which is calculated from themoieties is estimated as 3.2 (2) A
separation between the C7/N7/C11/C12/N8/C16 and C17/N9/
C21/C22/N10/C26 planes. Such short C  C contacts havepreviously been observed for some special cases {see, forÊ]
example, the value of the C  C separation [3.252 (2) A
reported for a one-dimensional-stacked nickel phthalocyanine
complex (Schramm et al., 1980)}. The two bpy planes de®nedby N7/N8/C7±C16 and N9/N10/C17±C26 exhibit r.m.s. deviaÊ , respectively. Moreover, eachtions of 0.03 (3) and 0.04 (3) A
bpy plane is nearly coplanar with the local equatorial coor-

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A side view of (II), showing three adjacent dimer units stacked in the[101] direction. H atoms have been omitted for clarity. [Symmetry codes:(i) 12 + x, 12 y, 12 + z; (ii) 12 + x, 12 y, 12 + z.]

A view showing the stacking of adjacent dimer units in (II). H atoms havebeen omitted for clarity. [Symmetry code: (i) 12 + x, 12 y, 12 + z.]
Acta Cryst. <"6=/ #" (>?

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dination plane: the dihedral angle between the N1/N4/N7/N8
and N7/N8/C7±C16 planes is 1.6 (3) , while the corresponding
angle between the N2/N5/N9/N10 and N9/N10/C17±C26
planes is 0.4 (3) .
The dimer further forms a one-dimensional stack in the[101] direction via ± stacking interactions between adjacentdimers (Fig. 6). However, the separation between adjacentÊ (see also Fig. 7), indibpy planes is estimated as 3.68 (4) A
cating that the intermolecular ± associations in (II) are
relatively weak in comparison with those achieved in (I). Thisimplies that the d(PtII)±(bpy) interactions achieved in (I)contribute signi®cantly to the relatively strong interdimer
stacking associations in (I).

*+ 

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In order to avoid complexation between the silver ion and the N,Ndimethylguanidinate ligand, compounds (I) and (II) were preparedfrom a hydroxo-bridged dimer, [Pt2(-OH)2(bpy)2](NO3)2 (Wimmer
et al., 1988). It is also noteworthy that the preparation of the pivalamidate-bridged analogue was carried out as a one-pot reaction of
PtCl2(bpy), silver nitrate and pivalamide (Yokokawa & Sakai, 2004).
For the synthesis of (I), a solution of PtCl2(bpy) (0.5 mmol,
0.221 g) and AgNO3 (1.0 mmol, 0.170 g) in water (10 ml) was re¯uxedin the dark for 3 h, followed by ®ltration to remove the precipitated
AgCl. To the ®ltrate were added [(CH3)2NC(:NH)NH2]2H2SO4(0.375 mmol, 0.102 g) and methanol (10 ml). After adjusting the pHof the mixture to 8, the solution was re¯uxed for 24 h, during whichtime the colour of the solution turned red±purple. The solution wasthen left at room temperature, followed by ®ltration to remove
insoluble material. To the resulting ®ltrate were added 7±8 drops of asaturated aqueous NH4PF6 solution. The resulting deep-green
powder was collected by ®ltration and dried in vacuo (yield 0.11 g).
The crude product was puri®ed on a Sephadex LH-20 column using
MeOH±CH3CN (1:1 v/v) as eluent. The ®rst and second deep-brownbands were assumed to correspond to compounds of higher nuclearity, although their identi®cation has been unsuccessful so far. The
third red±purple band, corresponding to (I), was collected and thesolution evaporated to dryness. The compound was redissolved in
CH3CN and recrystallized by leaving the solution at room temperature in air in a vial covered with aluminium foil, with several pin holes
made in the foil to allow the slow evaporation of the solvent (yield
9.6%). The acetonitrile disolvate, (I), easily loses solvent upon
exposure to air, so single-crystal X-ray diffractometry was carried out
on the solvated form. All other analytical data were obtained for the
non-solvated form of the complex, [PtII
2 (bpy)2(-dmg)2](PF6)2, as
follows: analysis calculated for C26H32F12N10P2Pt2: C 26.81, H 2.77, N
12.03%; found: C 26.54, H 2.48, N 11. 44%. IR (KBr, , cm 1): 3419
(w), 1607 (w), 1547 (m), 1453 (w), 1318 (w), 1176 (w), 1065 (w), 840(s), 768 (w), 558 (m); 1H NMR (CD3CN):  3.08 (s, 12H, methyl), 3.61
(s, 4H, NH), 7.35 (t, 4H, bpy), 7.54 (d, 4H, bpy), 8.02 (t, 4H, bpy), 8.70
(d, 4H, bpy); UV±vis absorption spectrum (CH3CN, 293 K, in air):
500 (" = 1990 M 1 cm 1, metal±metal-to-ligand charge-transferband), 312 nm (" = 18100 M 1 cm 1) and 251 nm (" =37800 M 1 cm 1).
For the synthesis of (II), a solution of PtCl2(bpy) (0.5 mmol,
0.221 g) and AgNO3 (1.0 mmol, 0.170 g) in water (10 ml) was re¯uxedin the dark for 3 h, followed by ®ltration to remove the precipitated
AgCl. The ®ltrate was then evaporated to dryness to give a solid et al.  @B"< (!4(="< !4"="D<B=" % < (4(=@B"< (!4(="<5?="< !4"="D45(electronic reprint",  

corresponding to [Pt2(-OH)2(bpy)2](NO3)2 (Wimmer et al., 1988).
To this were added [(CH3)2NC(:NH)NH2]2H2SO4 (0.375 mmol,
0.102 g) and water (2.5 ml). The solution was re¯uxed for 24 h, during
which time the colour of the solution changed to red. The solution
was allowed to stand at room temperature in air for a few days untilthe volume of the solution was greatly reduced. The deposited
product consisted of red crystals of an unidenti®ed by-product andorange prisms of (II). These two types of crystals were collected by®ltration, dried in air and manually separated under a microscope.
The total yield of the orange compound, (II), was 87 mg (13%).
Analysis calculated for C29H54N14O17Pt2S2: C 26.29, H 4.11, N
14.80%; found: C 26.43, H 3.34, N 15.10%. IR (KBr, , cm 1): 3364
(m, br), 1636 (m), 1603 (m), 1573 (m), 1541 (m), 1384 (s), 1118 (s),1030 (w), 766 (m), 618 (s), 420 (w).

!  
Crystal data
[Pt2(C3H8N3)2(C10H8N2)2](PF6)22C2H3N
Mr = 1246.84
Triclinic, P1
Ê
a = 12.527 (1) AÊ
b = 12.606 (1) AÊc = 13.3233 (11) A= 94.945 (1)= 94.621 (1)= 108.295 (1)Ê3
V = 1977.3 (3) A
Z=2
Dx = 2.094 Mg m 3
Mo K radiation
 = 7.25 mm 1
T = 100 (1) K
Square prism, dark red
0.21  0.16  0.09 mm. 

Ê ,  ) for (II).
Selected geometric parameters (APt1ÐPt2
Pt1ÐN1
Pt1ÐN4
Pt1ÐN7
Pt1ÐN8Pt2ÐN22.5656 (4)1.994 (6)1.980 (6)2.060 (6)2.041 (6)1.992 (6)Pt2ÐN5Pt2ÐN9Pt2ÐN10Pt1ÐO1
Pt2ÐO5
Pt1ÐPt2i

1.988 (6)2.045 (6)2.032 (6)2.152 (5)2.139 (5)7.5991 (4)N7  N9
N7  C17
N8  N10
N8  C22
N9  C11

3.157 (8)3.263 (10)3.135 (8)3.382 (9)3.352 (9)N10  C16
C7  C17
C12  C21
C16  C26

3.244 (10)3.324 (12)3.429 (10)3.278 (11)N4ÐPt1ÐN1
N4ÐPt1ÐN8
N1ÐPt1ÐN8
N4ÐPt1ÐN7
N1ÐPt1ÐN7
N8ÐPt1ÐN7
N4ÐPt1ÐO1
N1ÐPt1ÐO1
N8ÐPt1ÐO1
N7ÐPt1ÐO1

89.2 (3)96.0 (3)174.7 (3)176.4 (3)94.3 (3)80.5 (3)93.7 (2)92.0 (2)86.7 (2)85.3 (2)N5ÐPt2ÐN2
N5ÐPt2ÐN10
N2ÐPt2ÐN10
N5ÐPt2ÐN9
N2ÐPt2ÐN9N10ÐPt2ÐN9N5ÐPt2ÐO5
N2ÐPt2ÐO5
N10ÐPt2ÐO5
N9ÐPt2ÐO5

90.4 (3)94.5 (3)175.0 (3)173.7 (3)95.6 (3)79.6 (3)92.0 (2)93.6 (2)85.0 (2)85.7 (2)N4ÐPt1ÐPt2ÐN5
N1ÐPt1ÐPt2ÐN2

16.3 (3)17.5 (3)N8ÐPt1ÐPt2ÐN10
N7ÐPt1ÐPt2ÐN917.9 (3)18.6 (3)Symmetry code: (i) x  12; y  12; z  12.

Data collection
Bruker SMART APEX CCD areadetector diffractometer! scans
Absorption correction: multi-scan(SADABS; Sheldrick, 1996)
Tmin = 0.384, Tmax = 0.521

23482 measured re¯ections
8671 independent re¯ections
6882 re¯ections with I > 2(I)Rint = 0.045
max = 27.1

w = 1/[ 2(Fo2) + (0.0584P)2+ 40.2739P]
where P = (Fo2 + 2Fc2)/3(/)max < 0.001
Ê 3max = 4.41 e AÊ 3min = 2.80 e A

Ê ,  ) for (I).
Selected geometric parameters (APt1ÐPt2
Pt1ÐN1
Pt1ÐN4
Pt1ÐN7
Pt1ÐN82.8512 (6)1.993 (10)2.016 (9)2.016 (9)2.019 (9)Pt2ÐN2Pt2ÐN5Pt2ÐN9Pt2ÐN10Pt1  C11i
Pt1  C10i

3.416 (10)3.470 (13)Pt2  C21ii

3.361 (12)N1ÐPt1ÐN4
N1ÐPt1ÐN7
N4ÐPt1ÐN7
N1ÐPt1ÐN8
N4ÐPt1ÐN8
N7ÐPt1ÐN8

88.3 (4)174.1 (4)96.0 (4)95.3 (4)176.4 (4)80.4 (4)N5ÐPt2ÐN10
N5ÐPt2ÐN9N10ÐPt2ÐN9N5ÐPt2ÐN2
N10ÐPt2ÐN2
N9ÐPt2ÐN2

174.7 (4)95.1 (4)80.4 (4)87.6 (4)96.9 (4)177.0 (4)N4ÐPt1ÐPt2ÐN5
N8ÐPt1ÐPt2ÐN1022.0 (4)23.2 (4)N7ÐPt1ÐPt2ÐN9N1ÐPt1ÐPt2ÐN2

23.4 (4)21.3 (4)Symmetry codes: (i)x; y; z  1; (ii))-Ê3
V = 4786.2 (4) A
Z=4
Dx = 1.839 Mg m 3
Mo K radiation
 = 6.01 mm 1
T = 296 (2) K
Square prism, orange
0.25  0.14  0.07 mm

Data collection. %

x; y; z.

Crystal data
(C3H10N3)[Pt2(C3H8N3)2(SO4)2(C10H8N2)2]NO36H2O
Mr = 1325.16
Monoclinic, P21 =nÊ
a = 12.6189 (6) AÊ
b = 28.9553 (14) AÊc = 14.4197 (7) A= 114.712 (1)Re®nementRe®nement on F 2
R[F 2 > 2(F 2)] = 0.061
wR(F 2) = 0.154
S = 1.15
8671 re¯ections
497 parameters
H-atom parameters constrained!  2.030 (10)2.005 (10)2.027 (11)2.014 (9)Bruker SMART APEX CCD areadetector diffractometer! scans
Absorption correction: Gaussian(XPREP in SAINT; Bruker,
2001)
Tmin = 0.272, Tmax = 0.676

31986 measured re¯ections
11376 independent re¯ections
6677 re¯ections with I > 2(I)Rint = 0.066
max = 27.9

Re®nementRe®nement on F 2
R[F 2 > 2(F 2)] = 0.041
wR(F 2) = 0.114
S = 0.95
11376 re¯ections
568 parameters

H-atom parameters constrained
w = 1/[ 2(Fo2) + (0.0459P)2]
where P = (Fo2 + 2Fc2)/3(/)max = 0.003
Ê 3
max = 2.15 e AÊ 3min = 1.07 e A. "

Ê ).
Contact distances for (II) (AN7  N9
N7  C17
N8  N10
N8  C22
N9  C11

3.157 (8)3.263 (10)3.135 (8)3.382 (9)3.352 (9) et al.  @B"< (!4(="< !4"="D<B=" % < (4(=@B"< (!4(="<5?="< !4"="D45(electronic reprint

N10  C16
C7  C17
C12  C21
C16  C26

3.244 (10)3.324 (12)3.429 (10)3.278 (11)Acta Cryst. <"6=/ #" (>?

 . )

Ê ,  ) for (II).
Hydrogen-bond geometry (ADÐH  ADÐHH  AD  A

DÐH  A

N1ÐH1  O4
N2ÐH2  O7
N5ÐH5  O8
N11ÐH11B  O4
N12ÐH12B  O2
N11ÐH11A  O8ii
N12ÐH12A  O6iii

0.86
0.86
0.86
0.86
0.86
0.86
0.86

2.20
2.26
2.20
2.12
2.13
2.27
2.09

2.908 (9)2.854 (9)2.914 (8)2.973 (11)2.962 (10)3.102 (10)2.825 (9)

140
126
141
172
163
164
143

Symmetry codes: (ii)x  1; y; z  2; (iii) x  1; y; z  1.

Two PF6 anions in (I) show orientational disorder. Around each
P atom, there are two sets of possible positions, viz. F1A±F6A andF1B±F6B around P1, and F7A±F12A and F7B±F12B around P2. It
was assumed that the disordered F atoms around each P atom would
have the same isotropic displacement parameter. Furthermore, PÐFÊ , and the 12 cis F  F distances
distances were restrained to 1.55 (1) A
within each PF6 anion were restrained to be equal. The sum of theoccupation factors of sites A and B for each PF6 anion wasrestrained to unity. All H atoms of (I) were located in their idealized
Ê , aromatic CÐH = 0.95 AÊ andpositions, with methyl CÐH = 0.98 A
Ê , and included in the re®nement using aguanidinate NÐH = 0.88 A
riding model, with Uiso(H) = 1.5Ueq(methyl C), 1.2Ueq(aromatic C)
and 1.2Ueq(guanidinate N). In the ®nal difference Fourier synthesis ofÊ 3 were observed,(I), six residual peaks in the range 2.56±4.44 e A
primarily near the Pt atoms.
For compound (II), the nitrate anion was observed to be disordered over two sites, A and B. The disordered atoms were assumed tohave the same isotropic displacement parameter. Furthermore, theÊ , the three O  O
NÐO distances were restrained to 1.22 (1) A
distances were restrained to be equal, and the nitrate anion wasrestrained to be planar. The two sites were assumed to be equally
populated and therefore the occupation factors of the atoms were all®xed at 0.50. Two of the six water molecules were also observed to bedisordered over two sites (O16A/O16B and O17A/O17B). For each ofthem, the disordered atoms were assumed to have the same isotropic
displacement parameter, and the occupation factors of the atoms
were ®xed at 0.50, as for the nitrate geometry. All H atoms, except for
those of the water molecules, were located in their idealized positions,Ê , aromatic CÐH = 0.93 A
Ê and guanidinate
with methyl CÐH = 0.96 A
Ê , and included in the re®nement using a ridingNÐH = 0.86 A
model, with Uiso(H) = 1.5Ueq(methyl C), 1.2Ueq(aromatic C) and
1.2Ueq(guanidinate N). In the ®nal difference Fourier synthesis forÊ 3 were observed(II), six residual peaks in the range 1.03±2.15 e Anear the Pt atoms.

Acta Cryst. <"6=/ #" (>?

 

For both compounds, data collection: SMART (Bruker, 2001); cellre®nement: SAINT (Bruker, 2001); data reduction: SAINT;
program(s) used to solve structure: SHELXS97 (Sheldrick, 1997);
program(s) used to re®ne structure: SHELXL97 (Sheldrick, 1997);
molecular graphics: KENX (Sakai, 2004); software used to preparematerial for publication: SHELXL97, TEXSAN (Molecular Structure Corporation, 2001), KENX and ORTEPII (Johnson, 1976).

This work was partly supported by Grants-in-Aid for
Scienti®c Research (B) (grant No. 14340223) and (A) (grantNo. 17205008), and partly by a Grant-in-Aid for Scienti®cResearch on Priority Areas (grant No. 16074216 of 434,
`Chemistry of Coordination Space'), from the Ministry of
Education, Culture, Sports, Science and Technology of Japan.
Supplementary data for this paper are available from the IUCr electronicarchives (Reference: BM3021). Services for accessing these data aredescribed at the back of the journal.

/ 0Akiyama, N., Sato, N., Konno, Y., Sakai, K., Kajiwara, T. & Ito, T. (2000). Japan
Symposium on Coordination Chemistry, Ritsumeikan University, 16±18September, 2000. Paper No. 2P1-C08.
Bruker (2001). SAINT (Version 6.22) and SMART (Version 5.625). Bruker
AXS Inc., Madison, Wisconsin, USA.
Johnson, C. K. (1976). ORTEPII. Report ORNL-5138. Oak Ridge National
Laboratory, Tennessee, USA.
Molecular Structure Corporation (2001). TEXSAN. Version 1.11r1. MSC, The
Woodlands, Texas, USA.
Sakai, K. (1996). Unpublished results.
Sakai, K. (2004). KENX. Kyushu University, Japan.
Sakai, K., Ishigami, E., Konno, Y., Kajiwara, T. & Ito, T. (2002). J. Am. Chem.
Soc. 124, 12088±12089.
Sakai, K., Kurashima, M., Akiyama, N., Satoh, N., Kajiwara, T. & Ito, T. (2003).
Acta Cryst. C59, m345±m349.
Sakai, K., Takeshita, M., Tanaka, Y., Ue, T., Yanagisawa, M., Kosaka, M.,
Tsubomura, T., Ato, M. & Nakano, T. (1998). J. Am. Chem. Soc. 120, 11353±
11363.
Sakai, K., Tanaka, Y., Tsuchiya, Y., Hirata, K., Tsubomura, T., Iijima, S. &Bhattacharjee, A. (1998). J. Am. Chem. Soc. 120, 8366±8379.
Schramm, C. J., Scaringe, R. P., Stojakovic, D. R., Hoffman, B. M., Ibers, J. A. &Marks, T. J. (1980). J. Am. Chem. Soc. 102, 6702±6713.
Sheldrick, G. M. (1996). SADABS. University of GoÈttingen, Germany.
Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University ofGoÈttingen, Germany.
Wimmer, S., Castan, C., Wimmer, F. L. & Johnson, N. P. (1988). Inorg. Chim.
Acta, 142, 13±15.
Yokokawa, K. & Sakai, K. (2004). Acta Cryst. C60, m244±m247.

 et al.  @B"< (!4(="< !4"="D<B=" % < (4(=@B"< (!4(="<5?="< !4"="D45(electronic reprint)%