2446 Inorganic Chemistry, Vol. 15, No. 10, I976
Williams et al. Contribution from the Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
Structural Studies of Precursor and Partially Oxidized Conducting Complexes. 1. A Neutron Diffraction and Spectroscopic Investigation of Quasi-One-Dimensional Potassium Tetracyanoplatinate (1.75:l) Sesquihydrate, K1.75 [Pt(CN)4]. 1 . 5 H 2 O 1 JACK M. WILLIAMS,* KEITH D. KEEFER, DONALD M. WASHECHECK, and NANCY P. ENRIGHT* Received March 22, 1976
AIC601986
The complete molecular structure of quasi-one-dimensional, partially oxidized potassium tetracyanoplatinate (1.75:1) sesquihydrate, K1.75[Pt(CN)41.1.5H~O, has been determined by a single-crystal neutron diffraction study. The potassium deficient tetracyanoplatinate, K(def)TCP hereafter, crystallizes with four formula units in the triclinic unit cell Cil-Pl, with cell constants a = 10.360 (17) A, b = 9.303 (15) A, c = 11.832 (19) A, CY = 77.57 (9)O, /3 = 114.74 (5)O, and y = 73.64 (7)’. A total of 5037 observed data were averaged to yield 3969 independent reflections (3276 data with Fo2 > crFo2). The structure was solved from the neutron Patterson map and refinement using full-matrix least-squares techniques has led to an agreement factor of R(Fo2)= 0.058. The agreement factor for 3276 data with Fo2 > uFo2 is R(Fo2) = 0.054. The structure comprises an unusual “zig-zag” metal atom chain containing three crystallographically independent Pt atoms with a Pt(l)-Pt(2)-Pt(3) bond angle of 173.25 (3)’. Inversion centers occur at Pt(1) and Pt(3). The most surprising finding is that the two independent metal atom separations are equal [2.961 (1) and 2.965 (1) A], though not required , ~ . ~they H~O are 2.888 (6) 8, and 2.892 (6) A. The to be so by symmetry, just as in the case of K ~ [ P ~ ( C N ) ~ ] B ~ Owhere short Pt-Pt separations and almost totally non-eclipsed configuration of adjacent Pt(CN)4-1.75groups (torsion angles between adjacent platinocyanide groups ranging from 38.46 to 51.82’) are indicative of considerable Pt(Sd,i) metal overlap, strong metal-metal bond formation, and repulsive ~ - 7 r cyanide interactions. While Pt(1) and Pt(3) reside on the c axis, Pt(2) is displaced 0.170 (1) A normal to c. The deformation of the Pt atom chain is the result of an asymmetric electrostatic environment about Pt(2) involving K+.--NsC interactions. ’ Although the CY groups of Pt(2) form the greatest number (and shortest 0-Ha-N contacts) of water molecule to cyanide hydrogen bonds, the Pt chain deformation is not due to C=N--HzO hydrogen bond formation. The water molecules play an important role in the structure of the crystal, i.e., in addition to forming single and bifurcated hydrogen bonds, which bind adjacent Pt(CN)4-1.75groups in a single strand of a Pt-Pt chain, they also serve to cross-link Pt(CN)4-1,75groups of different Pt(CN)4-’.75 stacks. In addition to normal H-bonding interactions, all lone-pair orbitals appear to be directed toward K’ ions, increasing the binding of the water molecules. Also involved in the overall hydrogen bonding scheme is a disorder of one K+ ion and one HzO molecule. We have found no evidence for formation of an incommensurate superlattice. It appears that the Pt chain deformation originates in the asymmetric electrostatic lattice interactions and is not caused either by a charge density wave or a Peierls distortion. Preliminary results from neutron inelastic scattering studies confirm that strong electron-phonon coupling exists in K(def)TCP polarized specular reflectance data also indicate this salt is a “one-dimensional” metal at room temperature. The neutron inelastic scattering results are in accord with ongoing diffuse x-ray scattering experiments which confirm the existence of a Kohn anomaly in K(def)TCP. Crystal structure modifications now in progress are discussed which will, in principle, result in restoration of the Pt chain linearity in these cation deficient complexes and hopefully lead to enhanced metallic conductivity.
Introduction Partially oxidized one- and quasi-one-dimensional (1 -D) cyanoplatinate compounds continue to attract strong interest because of their high, nearly metallic electrical conductivities and they provide experimental results which greatly aid in the development of the theory of the one-dimensional state. The 1-D properties arise from the Pt atom “chains” formed in these compounds. The high conductivity is a result of short metal-metal separations within a chain allowing intrachain valence electron delocalization. The one-dimensional conduction properties and associated phenomena, such as Peierls’ distortions and charge density wave displacements, a r e all influenced to some degree by t h e crystalline environment of the metal-atom chains, viz., ligands, cations, anions, and lattice water molecules. We have undertaken a program of materials synthesis and detailed characterization of a wide range of one-dimensional compounds and their starting products. We are determining both t h e qualitative and quantitative effects of chemical and environmental factors on the conductivity of these compounds. W i t h this knowledge, chemical modifications have then been undertaken in order to amplify t h e most unusual properties of these novel compounds. T h e prototype compounds of this group a r e the anion deficient derivatives K ~ [ P ~ ( C N ) ~ ] X O , ~ .referred ~ H ~ O ,to as K C P ( B r ) and KCP(C1) where X is Br- or C1-, respectively. We have recently reported revised structures for K C P ( B r ) 3 and KCP(C1)4 determined using single-crystal neutron dif-
fraction techniques. Both of these structures contain an essential anion disorder resulting from the halide ion nonstoichiometry. The corresponding cation deficient tetracyanoplatinates provide a new structural modification and we recently reported the preliminary results of a neutron diffraction study5 of K1.75[Pt(CN)4].1.5H20, K(def)TCP. This metallic appearing salt contains a very unusual “zig-zag” Pt atom chain; hence, it is referred to as being a quasi-one-dimensional chain. In this paper we discuss the detailed chemical and molecular structure of K(def)TCP and the origin of t h e Pt chain distortion and present new information dealing with a K+-H20 disorder which we have discovered upon further analysis of our neutron diffraction d a t a . A recent single crystal x-ray analysis6 of K1,7j[Pt(CN)4].1 SH20 has also appeared which is in essential agreement with our findings. Finally we present structural comparisons between partially oxidized K2[Pt(CN)4]Br0.3.3.OH20, Ki.75[Pt(CN)4].1.5H20, and t h e unoxidized starting product7 K2[Pt(CN)4].3H20 which we have recently studied. F r o m a n analysis of these structural comparisons we predict the synthetic chemical modifications necessary to alter the Pt chain deformation in these compounds and enhance 1-D conductivity.
Experimental Section Crystal Preparation. After preparation of K1,7j[Pt(CN)4].1,5H20 using a modified method outlined by L e ~ y , crystals ~ . ~ were grown by slow evaporation of a saturated aqueous solution in a desiccator over
h
Neutron Diffraction Investigation of
Inorganic Chemistry, Vol. 15, No. 10, 1976 KI.~~[P~(CN)~J.~.~H~O
2441
Table La Published Structural Data on K,.,,[Pt(CN),]~l.SH,O Cell data Pobsd;
g/cm
Co mpd formulation K ,Pt JCN) , .6H,0b or K 1. ,[ Pt(CN),I *1.5H,O K, .,4[R(CN),I.1.8H,O
Crystal system
b , .4
p , deg
c, A A, deg
PCa’”d,‘
g/cm
vc,u, A3
Pt-Pt separation,A
Ref Levy’ (1912)
TriclinicC
Kl.,8[Pt(CN),]Br,~o,,~2H,0Triclinicd Ki.,,[Pt(CN),I.1.5H,O
a, ‘4 a, deg
Triclin&e [Ci’Pl] [ Z = 41
15.59 10.01 2.96 92.5 92.5 92.1 10.32 (1) 11.80 (1) 9.29 (1) 102.6 (1) 106.2 (1) 114.8 (1) 10.36 (2) 11.83 (2) 9.30 (2) 102.4 (1) 106.4 (1) 114.7 (1)
2.79 2.87
460.6
2.96
Krogmannand Hausen” (1968) 2.95 Minot et a1.’* (b/4 length) (1973) 2.96 This work (b/4 length)
(c length)
910.4 2.82 (1) 918.3 2.85
a The estimated standard deviations are given in parentheses and refer to the least-significant figures. Original formulation by Levy.’ Powder x-ray diffraction data; faint lines referred to as “superlattice” lines indicate c axis length should be doubled (5.92 A). Single crystal x-ray data. Triclinic cell data are those for the primitive Delauney-reduced cell. e Single crystal neutron data. Data for the primitive Delauney-reduced cell are given. X-ray powder patterns of this material are identical to that reported by Krogmann and Hausen” hence all c; b’ = a + b + ’ / 4 C ; and C’ = materials reported in this table appear to have the same molecular structure. The transform of a’ = a - 6 lI4cgives the cella’ = 15.592,6’ = 9.979, c’ = 2.958, a’ = 87.70, p‘ = 92.42, y‘ = 87.89 where a, b, and c refer to the cell in which data were collected.
*
+
magnesium perchlorate. This procedure yielded well-formed, bronze-colored crystals with dimensions typically 1-2 mm on a side and up to 30 mm in length. The compound Kl75[Pt(CN)4].1 .5H20 has been given various formulations as shown in Table I; however, from our work (vide infra) it is clear that all of these materials are structurally identical. First, although none of the unit cell constants reported in Table I match those,of Krogmann and Hausen,lo powder x-ray diffraction patterns of our crystals and of material prepared by Miller” agree perfectly with that published by Krogmann and Hausen.Io The Krogmann and Hausen unit cell may be derived from the cell reported in this work by considering it to consist only of Pt atoms and allowing c/4 translations as valid translational symmetry operations. This is not precisely true; however, x-ray powder patterns exhibit this pseudosymmetry. The transformation equation is given in Table I. Second, the triclinic Delauney-reduced cell parameters, which we have derived from our single crystal observations, are identical to those reported by Minot et aLL2The latter also reported the presence of a slight amount of Br- in their material. Chemical analysis13of our material for C, H, N, and halogen shows very good agreement with that obtained from our diffraction study. We have found that a trace of halogen ( U ( F ~ )out ~] to a maximum sin B/h = 0.72. Two reference reflections were remeasured after every 80 reflections in order to monitor instrument and crystal stability; their integrated intensities did not vary more than 3% during data collection. Each reflection was corrected for absorption (bc = 1.00 cm-I). The minimum and maximum transmission coefficients were 0.838 and 0.892, respectively. Using the absorption corrected integrated intensities the Fo2were obtained by application of the following equation:18 Fo2 = (wl sin 28)/(IoPNZV), where l o is the incident intensity, h the wavelength, w the angular velocity of rotation of the crystal, N the number of unit cells per unit volume, Ythe specimen volume, and 8 the Bragg angle. A cylindrical NaCl crystal, for which precise absorption and secondary extinction corrections had been made for all reflections, was used to obtain lo and thereby place the Fo2on an approximate “absolute scale” whereby the starting scale factor ( S ) in the least-squares refinement is 1.O. The variances of Fo2 were calculated from u2(FO2)= ac2(Fo2) (o.03F02)2,where aC2(Fo2) is determined from the counting statistics and 0.03 is an added factor deduced from the 3% maximum variation in the integrated intensities of the reference reflections.
-+
2448 Inorganic Chemistry, Vol. 15, No. 10, 1976
Williams et al.
Table 11. Final Discrepancy Indices Data selection
No. of reflections R(Fo) R ( F o 2 ) R,(FoZ)
u,'
All reflections 3969 0.077 0.077 0.082 1.45 3276 0.056 0.073 0.081 1.58 Fo2 > u(Fo2) Logic test* 3955 0.075 0.058 0.067 1.17 3262 0.053 0.054 0.065 1.27 Logic test* and FoZ > l.O(r(F02) a See text for explanation of u l , Data were excluded from the least-squares refinement if the transmission due to extinction was less than 40%.
*
T
Structure Solution and Refmement.16 The structure was solved using the neutron Patterson map from which the positions of the Pt(CN)4-l 75 groups were derived. It was obvious that adjacent Pt(CN)4-' 75 groups were stacked along c with a -45' staggered configuration of these groups. A full-matrix least-squares refinement of the Pt, C, and N positional parameters (with isotropic thermal parameters) yielded the following discrepancy indices:
RFO)=
ZIIFoI - IF,II ZIF, I
R ( F , ~ )=
= 0.40
Figure 1. The unit cell drawing of K,.,,[Pt(CN),]~1.5H,O showing the nonlinear Pt(l)-Pt(2)-Pt(S) chain which extends along c and has equal Pt-Pt separations [bond angle 173.25 (3)"]. Thermal ellipsoids are scaled to enclose 50% probability. Inversion centers occur at Pt(1) and Pt(3) only. The Pt(2) atom is displaced 0.170 A perpendicular to the c axis. Hydrogen bonds from H,O to cyanide group nitrogen atoms (N. . .H < 2.6 A] are indicated by faint lines and K+ ions are shown without bonding interactions.
IFo2 - Fc2I = 0.48 XF,2
and
Zwi IFo* - Fc21' Rlv(Fo2)=( C.wiF0
)
'I2
=0.55
indicated the structure to be centrosymmetric as follows: Theor
using all data. Fourier and difference Fourier maps were then calculated and all nonhydrogen atoms were located. An additional three cycles of least-squares refinement including Pt, C, and N atoms (anisotropic thermal parameters) and K and 0 atoms (isotropic thermal parameters) yielded R(F,) = 0.20, R(Fo)2= 0.24, and Rw(Fo2) = 0.29. At this stage all hydrogen atoms were located from a difference density map. An additional four cycles of least-squares refinement including 3Pt(CN)4, 3H20, and 4K+ with anisotropic temperature factors and all atoms at full occupancy yielded R(Fo) = 0.081, R ( F J 2 = 0.080, and R,(F0)* = 0.085. It was apparent at this point that an extinction correction was necessary and refinement was continued including an isotropic extinction parameter.19 In the final refinement 14 observations were rejected due to severe extinction (transmission factors
'I2
where n is the number of observations and p the number of parameters, varied (viz., 297) in the least-squares refinement, was 1.46 for all the data and the ratio of observations to parameters is ca. 14:l. Additional confirmation that the correct space group is P1 was obtained using statistical intensity tests in the program M U L T A ~l 6 which clearly
E' MOD(EZ- 1) MOD(E)
Exptl
Centric
Acentric
0.9995 1.0240 0.7725
1.0000 0.9680 0.7980
1.0000 0.7360 0.8860
The final positional and thermal parameters are given in Table I11 and the important bond distances and angles in K175[Pt(CN)4].1.5H20 are given in Table IV. For the least-squares refinement, the coherent neutron scattering amplitudes used for Pt, N, C , 0, K, and H were respectively 0.950,0.940,0.665,0.580,0.370, and -0.374 all in units of 10-12 cm.20
Structure Description The Zig-Zag Pt Atom Chain. The structure basically comprises Pt(CN)4-1.75groups which stack along the triclinic c axis to form an unusual quasi-one-dimensionalR atom chain. These stacks are bound by both water molecules and K+ ions indicating the main binding forces involve K+ to -N=C electrostatic attraction and dipolar H2Q--N=C interactions. The interactions of K+ with the cyanide nitrogen atoms of the platinocyanide groups appear to be the driving force for deformation of the Pt atom chain and will be discussed in detail shortly. The asymmetric unit of the crystal contains three crystallographically independent Pt(CN)4-1.75groups, four K+ ions (one in disorder), and three H20 molecules (one in disorder) and the unit cell is illustrated in Figure 1. The most significant and unusual finding is a nonlinear Pt atom chain as illustrated in the stereodiagram of the unit cell in Figure 2 . The zig-zag Pt atom chain comprises Pt(l), Pt(2), and Pt(3) [bond angle 173.25 (3)O] which extends along c. The Pt(2) is on a general position with z = 0.2568 (1) and is displaced perpendicular to the c axis (on which the other two Pt atoms reside) by 0.170 (1) A. The displacement is toward surrounding K+ ions and away from the coordinated H2Q molecules. Inversion centers occur at Pt(1) and Pt(3) and therefore what might be considered to be the basic repeat unit of the chain is a linear
Neutron Diffraction Investigation of K1,7~[Pt(CN)4]*1 SH20
Inorganic Chemistry, Vol. 15, No. 10, 1976 2449
Table 111. Positional and Thermal Parameters for K, .,,[Pt(CN),].l SH,O and Root-Mean-Square Thermal Displacements (in A) of Atoms along Their Principal Ellipsoidal AxePPb 104~
Wl)
0 93 (1) W2) M3) 0 C(11) 2308 (2) C(12) 513 (2) -1202 (2) C(21) C(22) 1991 (2) C(23) 1388 (2) C(24) -1856 (2) C(31) -2315 (2) C(32) -201 (2) N(11) 3652 (1) 879 (1) N(21) -1958 (1) N(22) 3018 (1) N(23) 2077 (1) N(24) -2996 (1) N(31) -3658 (1) N(32) -267 (2) K(1) 3999 (3) K(2) -2717 (5) K(3) -1121 (3) K(4)‘ 5079 (18) O(l1)‘ 3512 (6) O(12)’ 4031 (14) O(2) 5474 (3) 00) 4476 (3) H(11,l)‘ 4524 (8) H(11,2)’ 3020 (10) H(12,2)‘ 4786 (31) H(21) 4659(6) H(22) 5997 (6) H(31) 5391 (7) H(32) 4044 (7)
104~
0 -211 0 -621 (2) -2368 (2) -1477 (2) -2337 (2) 1064 (2) 1836 (2) 754(2) 2276 (2) -1030 (2) -3753 (1) -2205 (1) -3610(1) 1861 (2) 3022(1) 1172 (2) 3570 (1) 3952 (4) -3853 (4) 5011 (3) 265 (16) 2525 (7) 2475 (13) 5189 (3) 1694 (3) 2084 (7) 1954 (11) 2682 (41) 5945 (6) 4351 (6) 1121 (7) 988 (7)
1042
1044,.
0
5 3 (2) 48 (1) 49 (2) 67 (2) 79 (2) 66 (2) 61 (2) 68 (2) 60 (2) 53 (2) 88 (2) 71 (2) 127 (2) 98 (1) 87 (1) 112 (2) 81 (1) 56 (1) 168 (2) 101 (4) 229 (6) 121 (4) 80 (9) 100 (6) 248 (22) 151 (3) 132 (3) 192 (9) 230 (14) 333 (51) 189 (7) 209 (7) 212 (9) 266 (10)
2568(1) 5000 930 (2) 523 (2) 2317 (2) 3658(2) 2771 (2) 1514 (1) 4032 (2) 4432 (2) 1471 (1) 844 (1) 2154 (1) 4301 (1) 2820 (1) 924 (1) 3478 (1) 4106 (1) 3293 (3) 3918 (4) 1294 (3) 139 (16) 969 (7) 737 (12) 1997 (2) 5506 (3) 1706 (7) 1272 (8) 776 (40) 1140 (5) 1795 (5) 6342 (7) 5296 (8)
1 0 4 ~ 52 (2) 50 (1) 47 (2) 83 (2) 55 (2) 69 (2) 63 (2) 76 (2) 64 (2) 83 (2) 59 (2) 162 (2) 62(1) 102 (2) 80(1) 132 (2) 94 (2) 159 (2) 69 (1) 138 (4) 163 (5) 98 (4) 177 (25) 117 (6) 245 (14) 134 (3) 140 (3) 225 (8) 272 (16) 621 (86) 226 (8) 206 (7) 281 (11) 284 (10)
1
0
4
35 (1) 30(1) 31 (1) 55 (2) 51 (2) 47 (1) 44 (1) 51 (2) 42 (1) 44 (2) 43 (1) 81 (2) 83 (1) 72 (1) 67(1) 88 (2) 76 (1) 83 (2) 75 (1) 79 (3) 124 (5) 68 (3) 85 (13) 71 (6) 109 (11) 78 (3) 91 (3) 141 (9) 101 (9) 408 (70) 114 (6) 172 (7) 150 (8) 375 (15)
~
1 0 4 ~ 1 0 4 ~ 1 0 4 ~ 103u,
103~-
19 (1) -14 (1) 16 (1) -13 (1) 18 (1) -13 (1) 30 (1) -28 (1) 32 (1) -17 (1) 27 (1) -21 (1) 22 (1) -13 (1) 27 (1) -26 (1) 20 (1) -11 (1) 19 (1) -18 (1) 32 (1) -19 (1) 33 (1) -42 (1) 54 (1) -24 (1) 42 (1) -34 (1) 28 (1) -14(1) 47 (1) -46 (1) 30 (1) -6 (1) 23 (1) -38 (1) 65 (1) -27 (1) 46 (3) -38 (3) 136 (5) -81 (4) 48 (3) -30 (3) 43 (10) 6 (10) 17 (5) 18 (4) -10 (12) -13 (9) 38 (3) -25 (2) 46 (2) -40 (2) 31 (8) -54 (7) 34 (9) 45 (10) -23 (46) -254 (64) 51 (6) 8 (6) 115 (6) -98 (6) 30 (7) 13 (7) 205 (10) -230 (11)
131 (3) 133(2) 129 (2) 169 (2) 162 (2) 152 (2) 159 (2) 162 (2) 162 (2) 162(2) 145 (2) 211 (2) 206 (2) 190 (2) 198 (2) 212 (2) 210 (2) 222 (2) 187 (2) 198 (4) 212 (4) 185 (4) 188 (8) 170 (7) 264 (11) 222 (3) 217 (3) 289 (6) 230 (9) 416 (29) 287 (5) 281 (5) 337 (6) 280 (6)
-25 (1) -20(1) -16 (1) -37 (2) -32(1) -35 (1) -15 (1) -38 (1) -16 (1) -20 (1) -28 (1) -52 (1) -42(1) -64 (1) -3 (1) -86 (1) l(1) -30 (1) -58 (1) -20 (3) -114 (5) -55 (3) -16 (12) -83 (6) -136 (17) -19 (3) -61 (3) -55 (7) -214 (14) -98 (46) -55 (6) -81 (6) -53 (8) -186 (9)
129 (2) 122(2) 123 (2) 150 (2) 131 (2) 141 (2) 138 (2) 142 (2) 135 (2) 137 (2) 141 (2) 155 (2) 140 (2) 149 (2) 146 (2) 148 (2) 146 (2) 143 (2) 142 (2) 177 (4) 167 (5) 172 (4) 167 (6) 96 (11) 202 (11) 190 (3) 208 (3) 236 (8) 53 (24) 305 (24) 211 (6) 230 (6) 228 (6) 222 (6)
1 0 3 ~ ~
149 (2) 143 (1) 144 (2) 170 (2) 173 (2) 166 (2) 170 (2) 170(2) 167 (2) 178 (2) 184 (2) 239 (2) 219 (1) 208 (1) 224 (1) 235 (2) 239 (2) 245 (2) 252 (1) 249 (4) 300 (4) 214 (3) 304 (16) 300 (7) 417 (16) 282 (3) 240 (3) 346 (7) 441 (12) 652 (46) 342(6) 297 (6) 391 (8) 440 (8)
a The estimated standard deviations in parentheses for this and all subsequent tables refer t o the least-significant figure. &I The form of the temperature factor is exp (4, , h 2 0,,k2 03312+ 20, ,hk + 2SI3hl + 20,,kZ)]. Atoms in crystallographic disorder and multipliers were adjusted appropriately for partial occupanci.
+
+
Figure 2. Stereodrawing of the structure of triclinic K,,,,[Pt(CN),].l.SH,O which clearly illustrates both the “zig-zag” nature of the Pt atom chain and the molecular packing. One of the four K+ (at -0.5,0,0) is involved in disorder with one of the three H,O molecules [0(11) and 0(12), see Table 111 for coordinates].
three-atom array [Pt(Z)’-Pt( 1)-Pt(2) or alternatively Pt(2)-Pt(3)-Pt(2)’] where the bond angle [ 173.25 (3)O] between the three atom subunits indicates significant nonlinearity. However, the surprising finding (see Figure 1) is that the two crystallographically independent Pt-Pt bond lengths are of equal length [2.961 (1) and 2.965 (1) %.I and yet they exceed the distance in Pt metal (-2.78 A) by approximately 0.18 A.
The implications of the equality of the Pt-Pt separations are discussed below. The Pt(CN)4 Groups. The Pt(l)(CN)4-1.75 and Pt(3)(CN)4-1,75groups, associated with Pt atoms at centers of symmetry, are nearly planar as shown in Table V in which the best least-squares planes for these groups are presented. However, it is quite clear from Table V that the Pt(2) pla-
2450 Inorganic Chemistry, Vol. 15, No. 10, 1976
Williams et al.
Table IV. Interatomic Distances (A) and Bond Angles (deg) for K,.,,[Pt(CN),I.1 .5H20a (A) Distances around Platinum Atoms 2.965 (1) Pt(l)-Pt(2) 2.961 (1) Pt(2)-Pt(3) Pt(l)-C(11) 2.002 (1) Pt(2)-C(21) 1.996 (2) Pt(l)-C(12) 1.999 (1) Pt(2)-C(22) 2.008 (2) 2.004 (2) Pt(3)-C(3 1) 1.991 (1) Pt(2)-C(23) &(3)-C(32) 2.000 (1) Pt(2)-C(24) 1.991 (2) (Pt-C) Av 1.999 (4) (B) Carbon-Nitrogen Distances in Cyanide Groups C(ll)-N(11) 1.159 (2) C(21)-N(21) 1.156 (2) C(12)-N(12) 1.158 (2) C(22)-N(22) 1.157 (2) C(31)-N(31) 1.157 (2) C(23)-N(23) 1.160 (2) C(32)-N(32) 1.155 (2) C(24)-N(24) 1.159 (2) (C-N) AV 1.158 (6) (C) Potassium Ion Interactions K(1)-0(3) 2.734 (4) K(2)-O(3) 2.718 (4) K(1)-0(2) 2.864 (4) K(2)-0(2) 2.779 (4) K(l)-N(31) 2.899 (3) K(2)-N(21) 2.828 (3) K(l)-N(22) 2.912 (3) K(2)-N(32) 2.847 (4) K(l)-N(12) 3.002 (3) K(2)-N(22) 2.987 (3) K(l)-N(22)' 3.074 (3) K(3)-0(11) 2.677 (7) K(4)b-N(ll) 2.81 (2) K(3)-0(12) 2.807 (11) K(4)-N(21) 2.82 (2) K(3)-N(12) 2.811 (3) K(4)-N(ll) 2.87 (2) K(3)-N(32) 2.932 (3) K(4)-O(11) 2.88 (2) K(3)-N(24) 3.009 (3) K(4)-N(21)' 2.89 (2) K(3)-N(21) 3.018 (3) K(4)-N(21)" 3.01 (2) K(3)-H(11,12) 3.040 (8) K(3)-N(12) 3.077 (3) (D) Water Molecule 0-H Bond Distances O(ll)b-H(ll,l) 0.931 (9) 0(2)-H(21) 0.937 (6) O(ll)b-H(11,2)b 0.945 (7) 0(2)-H(22) 0.953 (6) 0(12)b-H(11,1) 0.97 (2) 0(3)-H(31) 0.930 (7) 0(12)b-H(12,2)b 0.84 (4) 0(3)-H(32) 0.915 (6) (E) Interatomic Distances and Angles Involving Hydrogen Atoms 0(ll)b-N(31) 2.832 (6) 0(11)b-H(11,1)-N(31) 165.5 (7) H(ll,l)-N(31) 1.921 (7) 0(ll)b-N(23) 3.169 (6) 0(ll)b-H(11,2)b-N(23) 137 (1) H(11,2)b-N(23) 2.41 (1) O(ll)b-N(ll) 3.181 (6) 0(ll)b-H(11,2)b-N(11) 120 (1) H(11,2)b-N(11) 2.60 (1) 0(12)b-N(24)C 3.18 (1) 0(12)b-H(12,2)b-N(24)c 175 (3) H(12,2)b-N(24)C 2.34 (4) 0(2)-N(24)d 3.000 (3) 0(2)-H(21)-N(24)d 161.6 (5) H(21)-N(24)d 2.096 (5) 0(2)-N(24)' 3.028 (3) 0(2)-H(22)-N(24)' 165.0 (4) H(22)-N(24)' 2.098 (5) O(3)-N( 1l)e 3.083 (3) 0(3)-H(31)-N( 1l)e 138.6 (6) H(31)-N(ll)e 2.324 (8) 0(3)-N(31)f 3.1 64 (3) 0(3)-H(32)-N( 3 l)f 135.5 (7) H(32)-N(31)f 2.446 (6) 0(3)-N(23)g 3.496 (3) 0(3)-H(32)-N(23) 115.3 (6) H(32)-N(23) 2.538 (8) (F) Angles within the Platinum Cyanide Groups Pt(1)-C(l1)-N(l1) 177.8 (1) Pt(2)
